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73410715 | 10.1007/s00023-018-0694-2 | We present an extended version of Riemannian geometry suitable for the
description of current formulations of double field theory (DFT). This
framework is based on graded manifolds and it yields extended notions of
symmetries, dynamical data and constraints. In special cases, we recover
general relativity with and without 1-, 2- and 3-form gauge potentials as well
as DFT. We believe that our extended Riemannian geometry helps to clarify the
role of various constructions in DFT. For example, it leads to a covariant form
of the strong section condition. Furthermore, it should provide a useful step
towards global and coordinate invariant descriptions of T- and U-duality
invariant field theories.Comment: v2: 50 pages, typos corrected, published versio | Extended Riemannian Geometry I: Local Double Field Theory | extended riemannian geometry i: local double field theory | riemannian formulations graded manifolds notions symmetries constraints. recover relativity potentials dft. believe riemannian helps clarify constructions dft. covariant condition. coordinate descriptions duality pages typos corrected versio | non_dup | [] |
83858456 | 10.1007/s00023-018-0696-0 | We consider the following generalized derivative nonlinear Schr\"odinger
equation \begin{equation*}
i\partial_tu+\partial^2_xu+i|u|^{2\sigma}\partial_xu=0,\ (t,x)\in\mathbb
R\times\mathbb R \end{equation*} when $\sigma\in(0,1)$. The equation has a
two-parameter family of solitary waves
$$u_{\omega,c}(t,x)=\Phi_{\omega,c}(x)e^{i\omega t+\frac{ic}2x-\frac
i{2\sigma+2}\int_0^x\Phi_{\omega,c}(y)^{2\sigma}dy},$$ with $(\omega,c)$
satisfying $\omega>c^2/4$, or $\omega=c^2/4$ and $c>0$. The stability theory in
the frequency region $\omega>c^2/4$ was studied previously. In this paper, we
prove the stability of the solitary wave solutions in the endpoint case
$\omega=c^2/4$ and $c>0$ | Orbital stability of solitary waves for generalized derivative nonlinear
Schr\"odinger equations in the endpoint case | orbital stability of solitary waves for generalized derivative nonlinear schr\"odinger equations in the endpoint case | schr odinger begin sigma mathbb mathbb sigma solitary omega omega omega frac frac sigma omega sigma omega satisfying omega omega omega previously. solitary endpoint omega | non_dup | [] |
129352172 | 10.1007/s00023-018-0697-z | We consider the systematic force on a heavy probe induced by interaction with
an overdamped diffusive medium where particles undergo a rotating force around
a fixed center. The stiffness matrix summarizes the stability of the probe
around that center, where the induced force vanishes. We prove that the
introduction of the rotational force in general enhances the stability of that
point (and may turn it from unstable to stable!), starting at second-order in
the nonequilibrium amplitude. When the driving is further enhanced the
stabilization occurs for a wide range of rotation profiles and the induced
stiffness converges to a universal expression proportional to the average
mechanical stiffness. The model thus provides a rigorous example of
stabilization of a fixed point due to contact with a nonequilibrium medium and
beyond linear order around equilibrium.Comment: 32 page | Stabilization in the eye of a cyclone | stabilization in the eye of a cyclone | overdamped diffusive undergo rotating center. stiffness summarizes vanishes. rotational enhances unstable nonequilibrium amplitude. driving stabilization stiffness converges universal stiffness. rigorous stabilization nonequilibrium | non_dup | [] |
129351290 | 10.1007/s00023-018-0698-y | We consider symmetric operators of the form $S := A\otimes I_{\mathfrak T} +
I_{\mathfrak H} \otimes T$ where $A$ is symmetric and $T = T^*$ is (in general)
unbounded. Such operators naturally arise in problems of simulating point
contacts to reservoirs. We construct a boundary triplet $\Pi_S$ for $S^*$
preserving the tensor structure. The corresponding $\gamma$-field and Weyl
function are expressed by means of the $\gamma$-field and Weyl function
corresponding to the boundary triplet $\Pi_A$ for $A^*$ and the spectral
measure of $T$. Applications to 1-D Schr\"odinger and Dirac operators are
given. A model of electron transport through a quantum dot assisted by cavity
photons is proposed. In this model the boundary operator is chosen to be the
well-known Jaynes-Cumming operator which is regarded as the Hamiltonian of the
quantum dot | Boundary triplets, tensor products and point contacts to reservoirs | boundary triplets, tensor products and point contacts to reservoirs | otimes mathfrak mathfrak otimes unbounded. naturally arise simulating contacts reservoirs. triplet preserving structure. gamma weyl gamma weyl triplet schr odinger dirac given. assisted cavity photons proposed. jaynes cumming regarded | non_dup | [] |
141538139 | 10.1007/s00023-018-0701-7 | This paper presents a thorough analysis of 1-dimensional Schroedinger
operators whose potential is a linear combination of the Coulomb term 1/r and
the centrifugal term 1/r^2. We allow both coupling constants to be complex.
Using natural boundary conditions at 0, a two parameter holomorphic family of
closed operators is introduced. We call them the Whittaker operators, since in
the mathematical literature their eigenvalue equation is called the Whittaker
equation. Spectral and scattering theory for Whittaker operators is studied.
Whittaker operators appear in quantum mechanics as the radial part of the
Schroedinger operator with a Coulomb potential.Comment: 45 page | On radial Schroedinger operators with a Coulomb potential | on radial schroedinger operators with a coulomb potential | presents thorough schroedinger coulomb centrifugal complex. holomorphic introduced. call whittaker mathematical eigenvalue whittaker equation. whittaker studied. whittaker mechanics schroedinger coulomb | non_dup | [] |
73405041 | 10.1007/s00023-018-0703-5 | We determine the p->q norms of the Gaussian one-mode quantum-limited
attenuator and amplifier and prove that they are achieved by Gaussian states,
extending to noncommutative probability the seminal theorem "Gaussian kernels
have only Gaussian maximizers" (Lieb in Invent Math 102(1):179-208, 1990). The
quantum-limited attenuator and amplifier are the building blocks of quantum
Gaussian channels, which play a key role in quantum communication theory since
they model in the quantum regime the attenuation and the noise affecting any
electromagnetic signal. Our result is crucial to prove the longstanding
conjecture stating that Gaussian input states minimize the output entropy of
one-mode phase-covariant quantum Gaussian channels for fixed input entropy. Our
proof technique is based on a new noncommutative logarithmic Sobolev
inequality, and it can be used to determine the p->q norms of any quantum
semigroup.Comment: Annales Henri Poincar\'e (2018 | The One-Mode Quantum-Limited Gaussian Attenuator and Amplifier Have
Gaussian Maximizers | the one-mode quantum-limited gaussian attenuator and amplifier have gaussian maximizers | norms attenuator amplifier extending noncommutative seminal kernels maximizers lieb invent math attenuator amplifier blocks attenuation affecting electromagnetic signal. crucial longstanding conjecture stating minimize covariant entropy. noncommutative logarithmic sobolev inequality norms annales henri poincar | non_dup | [] |
141530191 | 10.1007/s00023-018-0706-2 | We exhibit a Hamel basis for the concrete $*$-algebra $\mathfrak{M}_o$
associated to monotone commutation relations realised on the monotone Fock
space, mainly composed by Wick ordered words of annihilators and creators. We
apply such a result to investigate spreadability and exchangeability of the
stochastic processes arising from such commutation relations. In particular, we
show that spreadability comes from a monoidal action implementing a dissipative
dynamics on the norm closure $C^*$-algebra $\mathfrak{M} =
\overline{\mathfrak{M}_o}$. Moreover, we determine the structure of spreadable
and exchangeable monotone stochastic processes using their correspondence with
sp\-reading invariant and symmetric monotone states, respectively.Comment: Ann. Henri Poincar\`e, to appea | Wick order, spreadability and exchangeability for monotone commutation
relations | wick order, spreadability and exchangeability for monotone commutation relations | exhibit hamel concrete mathfrak monotone commutation realised monotone fock composed wick ordered annihilators creators. spreadability exchangeability stochastic arising commutation relations. spreadability comes monoidal implementing dissipative norm closure mathfrak overline mathfrak spreadable exchangeable monotone stochastic correspondence reading monotone ann. henri poincar appea | non_dup | [] |
83837876 | 10.1007/s00023-018-0707-1 | We study an inverse scattering problem at fixed energy for radial magnetic
Schr{\"o}dinger operators on R^2 \ B(0, r\_0), where r\_0 is a positive and
arbitrarily small radius. We assume that the magnetic potential A satisfies a
gauge condition and we consider the class C of smooth, radial and compactly
supported electric potentials and magnetic fields denoted by V and B
respectively. If (V, B) and (\tilde{V} , \tilde{B}) are two couples belonging
to C, we then show that if the corresponding phase shifts $\delta$\_l and
\tilde{$\delta$}\_l (i.e. the scattering data at fixed energy) coincide for all
l $\in$ L, where L $\subset$ N^$\star$ satisfies the M{\"u}ntz condition
\sum\_{l$\in$L} \frac{1}{l} = +$\infty$, then V (x) = \tilde{V}(x) and B(x) =
\tilde{B}(x) outside the obstacle B(0, r\_0). The proof use the Complex Angular
Momentum method and is close in spirit to the celebrated B{\"o}rg-Marchenko
uniqueness Theorem | Inverse scattering at fixed energy for radial magnetic Schr{\"o}dinger
operators with obstacle in dimension two | inverse scattering at fixed energy for radial magnetic schr{\"o}dinger operators with obstacle in dimension two | schr dinger arbitrarily radius. satisfies compactly potentials denoted respectively. tilde tilde couples belonging shifts delta tilde delta i.e. coincide satisfies frac infty tilde tilde obstacle spirit celebrated marchenko uniqueness | non_dup | [] |
84094221 | 10.1007/s00023-018-0708-0 | Continuing the series of works following Weyl's one-term asymptotic formula
for the counting function $N(\lambda)=\sum_{n=1}^\infty(\lambda_n{-}\lambda)_-$
of the eigenvalues of the Dirichlet Laplacian and the much later found two-term
expansion on domains with highly regular boundary by Ivrii and Melrose, we
prove a two-term asymptotic expansion of the $N$-th Ces\`aro mean of the
eigenvalues of $\sqrt{-\Delta + m^2} - m$ for $m>0$ with Dirichlet boundary
condition on a bounded domain $\Omega\subset\mathbb R^d$ for $d\geq 2$,
extending a result by Frank and Geisinger for the fractional Laplacian ($m=0$)
and improving upon the small-time asymptotics of the heat trace $Z(t) =
\sum_{n=1}^\infty e^{-t \lambda_n}$ by Ba\~nuelos et al. and Park and Song.Comment: Ann. Henri Poincar\'e (2018 | Two-term spectral asymptotics for the Dirichlet pseudo-relativistic
kinetic energy operator on a bounded domain | two-term spectral asymptotics for the dirichlet pseudo-relativistic kinetic energy operator on a bounded domain | continuing weyl asymptotic counting lambda infty lambda lambda eigenvalues dirichlet laplacian ivrii melrose asymptotic eigenvalues sqrt delta dirichlet omega mathbb extending frank geisinger fractional laplacian improving asymptotics trace infty lambda nuelos park ann. henri poincar | non_dup | [] |
73991950 | 10.1007/s00023-018-0709-z | We present a general infinite volume limit construction of probability
measures obeying the Glimm-Jaffe axioms of Euclidean quantum field theory in
arbitrary space-time dimension. In particular, we obtain measures that may be
interpreted as corresponding to scalar quantum fields with arbitrary bounded
continuous self-interaction. It remains however an open problem whether this
general construction contains non-Gaussian measures.Comment: New title. Final version, to appear in Annales Henri Poincar\' | Infinite volume limits in Euclidean quantum field theory via
stereographic projection | infinite volume limits in euclidean quantum field theory via stereographic projection | infinite obeying glimm jaffe axioms euclidean dimension. interpreted interaction. title. annales henri poincar | non_dup | [] |
83840161 | 10.1007/s00023-018-0711-5 | We consider the Thomas--Fermi--Dirac--von~Weizs{\"a}cker model for a system
composed of infinitely many nuclei placed on a periodic lattice and electrons
with a periodic density. We prove that if the Dirac constant is small enough,
the electrons have the same periodicity as the nuclei. On the other hand if the
Dirac constant is large enough, the 2-periodic electronic minimizer is not
1-periodic, hence symmetry breaking occurs. We analyze in detail the behavior
of the electrons when the Dirac constant tends to infinity and show that the
electrons all concentrate around exactly one of the 8 nuclei of the unit cell
of size 2, which is the explanation of the breaking of symmetry. Zooming at
this point, the electronic density solves an effective nonlinear Schr\"odinger
equation in the whole space with nonlinearity $u^{7/3}-u^{4/3}$. Our results
rely on the analysis of this nonlinear equation, in particular on the
uniqueness and non-degeneracy of positive solutions | Symmetry breaking in the periodic Thomas--Fermi--Dirac--von
Weizs{\"a}cker model | symmetry breaking in the periodic thomas--fermi--dirac--von weizs{\"a}cker model | thomas fermi dirac weizs cker composed infinitely nuclei placed density. dirac periodicity nuclei. dirac minimizer breaking occurs. analyze dirac tends infinity concentrate nuclei explanation breaking symmetry. zooming solves schr odinger nonlinearity rely uniqueness degeneracy | non_dup | [] |
129362688 | 10.1007/s00023-018-0712-4 | In this paper we introduce a simple field theoretic version of the
Carrozza-Tanasa-Klebanov-Tarnopolsky (CTKT) "uncolored" holographic tensor
model. It gives a more familiar interpretation to the previously abstract modes
of the SYK or CTKT models in terms of momenta. We choose for the tensor
propagator the usual Fermionic propagator of condensed matter, with a spherical
Fermi surface, but keep the CTKT interactions. Hence our field theory can also
be considered as an ordinary condensed matter model with a non-local and
non-rotational invariant interaction. Using a multiscale analysis we prove that
this field theory is just renormalizable to all orders of perturbation theory
in the ultraviolet regime.Comment: 24 pages, 2 figure | A Renormalizable SYK-type Tensor Field Theory | a renormalizable syk-type tensor field theory | theoretic carrozza tanasa klebanov tarnopolsky ctkt uncolored holographic model. familiar ctkt momenta. propagator usual fermionic propagator condensed spherical fermi keep ctkt interactions. ordinary condensed rotational interaction. multiscale renormalizable orders perturbation ultraviolet pages | non_dup | [] |
83860747 | 10.1007/s00023-018-0715-1 | A tripartite state $\rho_{ABC}$ forms a Markov chain if there exists a
recovery map $\mathcal{R}_{B \to BC}$ acting only on the $B$-part that
perfectly reconstructs $\rho_{ABC}$ from $\rho_{AB}$. To achieve an approximate
reconstruction, it suffices that the conditional mutual information
$I(A:C|B)_{\rho}$ is small, as shown recently. Here we ask what conditions are
necessary for approximate state reconstruction. This is answered by a lower
bound on the relative entropy between $\rho_{ABC}$ and the recovered state
$\mathcal{R}_{B\to BC}(\rho_{AB})$. The bound consists of the conditional
mutual information and an entropic correction term that quantifies the
disturbance of the $B$-part by the recovery map.Comment: v2: 18 pages, final version published in Annales Henri Poincar\' | Necessary criterion for approximate recoverability | necessary criterion for approximate recoverability | tripartite markov recovery mathcal acting perfectly reconstructs approximate reconstruction suffices conditional mutual recently. approximate reconstruction. answered recovered mathcal conditional mutual entropic quantifies disturbance recovery pages annales henri poincar | non_dup | [] |
42638812 | 10.1007/s00023-018-0716-0 | The data processing inequality states that the quantum relative entropy
between two states $\rho$ and $\sigma$ can never increase by applying the same
quantum channel $\mathcal{N}$ to both states. This inequality can be
strengthened with a remainder term in the form of a distance between $\rho$ and
the closest recovered state $(\mathcal{R} \circ \mathcal{N})(\rho)$, where
$\mathcal{R}$ is a recovery map with the property that $\sigma = (\mathcal{R}
\circ \mathcal{N})(\sigma)$. We show the existence of an explicit recovery map
that is universal in the sense that it depends only on $\sigma$ and the quantum
channel $\mathcal{N}$ to be reversed. This result gives an alternate,
information-theoretic characterization of the conditions for approximate
quantum error correction.Comment: v3: 24 pages, 1 figure, final version published in Annales Henri
Poincar\' | Universal recovery maps and approximate sufficiency of quantum relative
entropy | universal recovery maps and approximate sufficiency of quantum relative entropy | inequality sigma never mathcal states. inequality strengthened remainder closest recovered mathcal circ mathcal mathcal recovery sigma mathcal circ mathcal sigma recovery universal sigma mathcal reversed. alternate theoretic approximate pages annales henri poincar | non_dup | [] |
83857813 | 10.1007/s00023-018-0717-z | We present an operator-algebraic approach to the quantization and reduction
of lattice field theories. Our approach uses groupoid C*-algebras to describe
the observables and exploits Rieffel induction to implement the quantum gauge
symmetries. We introduce direct systems of Hilbert spaces and direct systems of
(observable) C*-algebras, and, dually, corresponding inverse systems of
configuration spaces and (pair) groupoids. The continuum and thermodynamic
limit of the theory can then be described by taking the corresponding limits,
thereby keeping the duality between the Hilbert space and observable C*-algebra
on the one hand, and the configuration space and the pair groupoid on the
other. Since all constructions are equivariant with respect to the gauge group,
the reduction procedure applies in the limit as well.Comment: 23 pages, 6 figure | Quantum lattice gauge fields and groupoid C*-algebras | quantum lattice gauge fields and groupoid c*-algebras | algebraic quantization theories. groupoid algebras observables exploits rieffel implement symmetries. hilbert observable algebras dually groupoids. continuum thermodynamic thereby keeping duality hilbert observable groupoid other. constructions equivariant applies pages | non_dup | [] |
141533158 | 10.1007/s00023-018-0718-y | We relate the amount of entanglement required to play linear-system non-local
games near-optimally to the hyperlinear profile of finitely-presented groups.
By calculating the hyperlinear profile of a certain group, we give an example
of a finite non-local game for which the amount of entanglement required to
play $\varepsilon$-optimally is at least $\Omega(1/\varepsilon^k)$, for some
$k>0$. Since this function approaches infinity as $\varepsilon$ approaches
zero, this provides a quantitative version of a theorem of the first author.Comment: 27 pages. v2: improved results based on a suggestion by N. Ozaw | Entanglement in non-local games and the hyperlinear profile of groups | entanglement in non-local games and the hyperlinear profile of groups | relate entanglement games optimally hyperlinear finitely groups. calculating hyperlinear game entanglement varepsilon optimally omega varepsilon infinity varepsilon pages. suggestion ozaw | non_dup | [] |
83850778 | 10.1007/s00023-018-0723-1 | We investigate the free boundary Schur process, a variant of the Schur
process introduced by Okounkov and Reshetikhin, where we allow the first and
the last partitions to be arbitrary (instead of empty in the original setting).
The pfaffian Schur process, previously studied by several authors, is recovered
when just one of the boundary partitions is left free. We compute the
correlation functions of the process in all generality via the free fermion
formalism, which we extend with the thorough treatment of "free boundary
states". For the case of one free boundary, our approach yields a new proof
that the process is pfaffian. For the case of two free boundaries, we find that
the process is not pfaffian, but a closely related process is. We also study
three different applications of the Schur process with one free boundary:
fluctuations of symmetrized last passage percolation models, limit shapes and
processes for symmetric plane partitions, and for plane overpartitions.Comment: 58 pages, 17 figures (v3: final version, with fewer pages than v2 to
comply with journal requirements. In particular Theorems 2.2 and 2.5 are now
stated under slightly more restrictive assumptions to simplify presentation.
Added Remarks 2.11, 2.12, 5.14 and 6.9 about the transition from pfaffian to
determinantal in the bulk. | The free boundary Schur process and applications I | the free boundary schur process and applications i | schur variant schur okounkov reshetikhin partitions empty pfaffian schur recovered partitions free. generality fermion formalism extend thorough pfaffian. boundaries pfaffian closely schur symmetrized passage percolation shapes partitions pages fewer pages comply requirements. theorems stated restrictive assumptions simplify presentation. remarks pfaffian determinantal bulk. | non_dup | [] |
83855829 | 10.1007/s00023-018-0728-9 | We investigate quantum graphs with infinitely many vertices and edges without
the common restriction on the geometry of the underlying metric graph that
there is a positive lower bound on the lengths of its edges. Our central result
is a close connection between spectral properties of a quantum graph and the
corresponding properties of a certain weighted discrete Laplacian on the
underlying discrete graph. Using this connection together with spectral theory
of (unbounded) discrete Laplacians on infinite graphs, we prove a number of new
results on spectral properties of quantum graphs. Namely, we prove several
self-adjointness results including a Gaffney type theorem. We investigate the
problem of lower semiboundedness, prove several spectral estimates (bounds for
the bottom of spectra and essential spectra of quantum graphs, CLR-type
estimates) and study spectral types.Comment: Dedicated to the memory of M. Z. Solomyak (16.05.1931 - 31.07.2016 | Spectral Theory of Infinite Quantum Graphs | spectral theory of infinite quantum graphs | infinitely restriction lengths edges. connection weighted laplacian graph. connection unbounded laplacians infinite graphs. adjointness gaffney theorem. semiboundedness bounds dedicated solomyak | non_dup | [] |
129354037 | 10.1007/s00023-018-0730-2 | We analyze the relative entropy of certain KMS states for scalar
self-interacting quantum field theories over Minkowski backgrounds that have
been recently constructed by Fredenhagen and Lindner in [FL14] in the framework
of perturbative algebraic quantum field theory. The definition we are using is
a generalization of the Araki relative entropy to the case of field theories.
In particular, we shall see that the analyzed relative entropy is positive in
the sense of perturbation theory, hence, even if the relative modular operator
is not at disposal in this context, the proposed extension is compatible with
perturbation theory. In the second part of the paper we analyze the adiabatic
limits of these states showing that also the density of relative entropy
obtained dividing the relative entropy by the spatial volume of the region
where interaction takes place is positive and finite. In the last part of the
paper we discuss the entropy production for states obtained by an ergodic mean
(time average) of perturbed KMS states evolved with the free evolution recently
constructed by the authors of the present paper. We show that their entropy
production vanishes even if return to equilibrium [Ro73, HKT74] does not hold.
This means that states constructed in this way are thermodynamically simple,
namely they are not so far from equilibrium states.Comment: 31 page | Relative entropy and entropy production for equilibrium states in pAQFT | relative entropy and entropy production for equilibrium states in paqft | analyze interacting minkowski backgrounds fredenhagen lindner perturbative algebraic theory. generalization araki theories. perturbation modular disposal compatible perturbation theory. analyze adiabatic dividing finite. ergodic perturbed evolved paper. vanishes return hold. thermodynamically | non_dup | [] |
84091713 | 10.1007/s00023-018-0732-0 | We analyze a general class of difference operators $H_\varepsilon =
T_\varepsilon + V_\varepsilon$ on $\ell^2(\varepsilon\mathbf{Z}^d)$, where
$V_\varepsilon$ is a multi-well potential and $\varepsilon$ is a small
parameter. We derive full asymptotic expansions of the prefactor of the
exponentially small eigenvalue splitting due to interactions between two
"wells" (minima) of the potential energy, i.e., for the discrete tunneling
effect. We treat both the case where there is a single minimal geodesic (with
respect to the natural Finsler metric induced by the leading symbol
$h_0(x,\xi)$ of $H_\varepsilon$) connecting the two minima and the case where
the minimal geodesics form an $\ell+1$ dimensional manifold, $\ell\geq 1$.
These results on the tunneling problem are as sharp as the classical results
for the Schr\"odinger operator in \cite{hesjo}. Technically, our approach is
pseudodifferential and we adapt techniques from \cite{hesjo2} and \cite{hepar}
to our discrete setting.Comment: 32 pages, 1 figur | Tunneling for a class of Difference Operators: Complete Asymptotics | tunneling for a class of difference operators: complete asymptotics | analyze varepsilon varepsilon varepsilon varepsilon mathbf varepsilon varepsilon parameter. derive asymptotic expansions prefactor exponentially eigenvalue splitting wells minima i.e. tunneling effect. treat geodesic finsler symbol varepsilon connecting minima geodesics manifold tunneling sharp schr odinger cite hesjo technically pseudodifferential adapt cite hesjo cite hepar pages figur | non_dup | [] |
86419143 | 10.1007/s00023-018-0735-x | Under suitable hypotheses, a symplectic map can be quantized as a sequence of
unitary operators acting on the $N$th powers of a positive line bundle over a
K\"{a}hler manifold. We show that if the symplectic map has polynomial decay of
correlations, then there exists a density one subsequence of eigensections
whose masses and zeros become equidistributed in balls of logarithmically
shrinking radii of lengths $\lvert \log N \rvert^{-\gamma}$ for some constant
$\gamma > 0$ independent of $N$.Comment: The ergodicity assumption is relaxed from exponential to polynomial
decay of correlation | Log-scale equidistribution of zeros of quantum ergodic eigensections | log-scale equidistribution of zeros of quantum ergodic eigensections | hypotheses symplectic quantized unitary acting powers bundle hler manifold. symplectic subsequence eigensections zeros equidistributed balls logarithmically shrinking radii lengths lvert rvert gamma gamma .comment ergodicity relaxed exponential | non_dup | [] |
42749726 | 10.1007/s00023-018-0736-9 | Processes such as quantum computation, or the evolution of quantum cellular
automata are typically described by a unitary operation implemented by an
external observer. In particular, an interaction is generally turned on for a
precise amount of time, using a classical clock. A fully quantum mechanical
description of such a device would include a quantum description of the clock
whose state is generally disturbed because of the back-reaction on it. Such a
description is needed if we wish to consider finite sized autonomous quantum
machines requiring no external control. The extent of the back-reaction has
implications on how small the device can be, on the length of time the device
can run, and is required if we want to understand what a fully quantum
mechanical treatment of an observer would look like. Here, we consider the
implementation of a unitary by a finite sized device which we call the
"Quasi-Ideal clock", and show that the back-reaction on it can be made
exponentially small in the device's dimension with only a linear increase in
energy. As a result, an autonomous quantum machine need only be of modest size
and or energy. We are also able to solve a long-standing open problem by using
a finite sized quantum clock to approximate the continuous evolution of an
Idealised clock. The result has implications on the equivalence of different
paradigms of quantum thermodynamics, some which allow external control and some
which only allow autonomous thermal machines.Comment: Main text: 9 + 53 pages. V4: Close to the published version, J.
Annales Henri Poincar\'e (2018) [Communicated by David P\'erez-Garc\'ia | Autonomous quantum machines and the finite sized Quasi-Ideal clock | autonomous quantum machines and the finite sized quasi-ideal clock | automata unitary implemented observer. turned precise clock. clock disturbed wish sized autonomous machines requiring control. want observer look like. unitary sized call quasi ideal clock exponentially energy. autonomous machine modest energy. solve standing sized clock approximate idealised clock. equivalence paradigms thermodynamics autonomous pages. annales henri poincar communicated david erez garc | non_dup | [] |
93956399 | 10.1007/s00023-018-0742-y | This work presents some results about Wick polynomials of a vector field
renormalization in locally covariant algebraic quantum field theory in curved
spacetime. General vector fields are pictured as sections of natural vector
bundles over globally hyperbolic spacetimes and quantized through the known
functorial machinery in terms of local $^*$-algebras. These quantized fields
may be defined on spacetimes with given classical background fields, also
sections of natural vector bundles, in addition to the Lorentzian metric. The
mass and the coupling constants are in particular viewed as background fields.
Wick powers of the quantized vector field are axiomatically defined imposing in
particular local covariance, scaling properties and smooth dependence on smooth
perturbation of the background fields. A general classification theorem is
established for finite renormalization terms (or counterterms) arising when
comparing different solutions satisfying the defining axioms of Wick powers.
The result is specialized to the case of general tensor fields. In particular,
the case of a vector Klein-Gordon field and the case of a scalar field
renormalized together with its derivatives are discussed as examples. In each
case, a more precise statement about the structure of the counterterms is
proved. The finite renormalization terms turn out to be finite-order
polynomials tensorially and locally constructed with the backgrounds fields and
their covariant derivatives whose coefficients are locally smooth functions of
polynomial scalar invariants constructed from the so-called marginal subset of
the background fields. The notion of local smooth dependence on polynomial
scalar invariants is made precise in the text.Comment: 63 pages, 2 figures, typos corrected, some comments added, accepted
for publication in Annales Henri Poincar\' | On Wick polynomials of boson fields in locally covariant algebraic QFT | on wick polynomials of boson fields in locally covariant algebraic qft | presents wick polynomials renormalization locally covariant algebraic curved spacetime. pictured bundles globally hyperbolic spacetimes quantized functorial machinery algebras. quantized spacetimes bundles lorentzian metric. viewed fields. wick powers quantized axiomatically imposing covariance perturbation fields. renormalization counterterms arising satisfying defining axioms wick powers. specialized fields. klein gordon renormalized derivatives examples. precise statement counterterms proved. renormalization polynomials tensorially locally backgrounds covariant derivatives locally invariants marginal fields. notion invariants precise pages typos corrected comments publication annales henri poincar | non_dup | [] |
146474277 | 10.1007/s00023-019-00767-6 | The existence and construction of exponentially localised Wannier functions
for insulators is a well-studied problem. In comparison, the case of metallic
systems has been much less explored, even though localised Wannier functions
constitute an important and widely used tool for the numerical band
interpolation of metallic condensed matter systems. In this paper we prove
that, under generic conditions, $N$ energy bands of a metal can be exactly
represented by $N+1$ Wannier functions decaying faster than any polynomial. We
also show that, in general, the lack of a spectral gap does not allow for
exponential decay.Comment: 18 pages, 4 figure | Localised Wannier functions in metallic systems | localised wannier functions in metallic systems | exponentially localised wannier insulators problem. metallic explored localised wannier constitute widely interpolation metallic condensed systems. generic wannier decaying faster polynomial. exponential pages | non_dup | [] |
2343194 | 10.1007/s00024-003-2397-x | Based on recent results in extreme value theory, we use a new technique for
the statistical estimation of distribution tails. Specifically, we use the
Gnedenko-Pickands-Balkema-de Haan theorem, which gives a natural limit law for
peak-over-threshold values in the form of the Generalized Pareto Distribution
(GPD). Useful in finance, insurance, hydrology, we investigate here the
earthquake energy distribution described by the Gutenberg-Richter seismic
moment-frequency law and analyze shallow earthquakes (depth h < 70 km) in the
Harvard catalog over the period 1977-2000 in 18 seismic zones. The whole GPD is
found to approximate the tails of the seismic moment distributions quite well
above moment-magnitudes larger than mW=5.3 and no statistically significant
regional difference is found for subduction and transform seismic zones. We
confirm that the b-value is very different in mid-ocean ridges compared to
other zones (b=1.50=B10.09 versus b=1.00=B10.05 corresponding to a power law
exponent close to 1 versus 2/3) with a very high statistical confidence. We
propose a physical mechanism for this, contrasting slow healing ruptures in
mid-ocean ridges with fast healing ruptures in other zones. Deviations from the
GPD at the very end of the tail are detected in the sample containing
earthquakes from all major subduction zones (sample size of 4985 events). We
propose a new statistical test of significance of such deviations based on the
bootstrap method. The number of events deviating from the tails of GPD in the
studied data sets (15-20 at most) is not sufficient for determining the
functional form of those deviations. Thus, it is practically impossible to give
preference to one of the previously suggested parametric families describing
the ends of tails of seismic moment distributions.Comment: pdf document of 21 pages + 2 tables + 20 figures (ps format) + one
file giving the regionalizatio | Characterization of the frequency of extreme events by the Generalized
Pareto Distribution | characterization of the frequency of extreme events by the generalized pareto distribution | extreme tails. gnedenko pickands balkema haan pareto finance insurance hydrology earthquake gutenberg richter seismic moment analyze shallow earthquakes harvard catalog seismic zones. approximate tails seismic moment moment magnitudes statistically subduction transform seismic zones. confirm ocean ridges zones exponent confidence. propose contrasting slow healing ruptures ocean ridges healing ruptures zones. deviations tail earthquakes subduction zones propose deviations bootstrap method. deviating tails determining deviations. practically impossible preference parametric families describing ends tails seismic moment document pages tables format file giving regionalizatio | non_dup | [] |
41147173 | 10.1007/s00024-004- | Employing 3D finite element method, we develop an algorithm to calculate gravity changes
due to pressurized sources of any shape in elastic and inelastic heterogeneous media. We
consider different source models, such as sphere, spheroid and sill, dilating in elastic media
(homogeneous and heterogeneous) and in elasto-plastic media. The models are oriented to
reproduce the gravity changes and the surface deformation observed at Campi Flegrei caldera
(Italy), during the 1982-84 unrest episode. The source shape and the characteristics of the
medium have great influence in the calculated gravity changes, leading to very different values
for the source densities. Indeed, the gravity residual strongly depends upon the shape of the
source. Non negligible contributions also come from density and rigidity heterogeneities within
the medium. Furthermore, if the caldera is elasto-plastic, the resulting gravity changes exhibit
a pattern similar to that provided by a low effective rigidity. Even if the variation of the source volumes is quite similar for most of the models considered, the density inferred for the
source ranges from ∼ 400 kg/m3 (supercritical water) to ∼ 3300 kg/m3 (higher than trachytic
basalts), with drastically different implications for risk assessment | Gravity changes due to overpressure sources in 3D heterogeneous media: application to Campi Flegrei caldera, Italy | gravity changes due to overpressure sources in 3d heterogeneous media: application to campi flegrei caldera, italy | employing pressurized elastic inelastic heterogeneous media. sphere spheroid sill dilating elastic homogeneous heterogeneous elasto plastic media. oriented reproduce deformation campi flegrei caldera unrest episode. great densities. residual source. negligible come rigidity heterogeneities medium. caldera elasto plastic exhibit rigidity. volumes inferred ranges supercritical trachytic basalts drastically | non_dup | [] |
41760728 | 10.1007/s00024-004-0386-9 | A non-standard new code to solve multiphase viscous thermo–mechanical problems applied to geophysics is presented. Two numerical methodologies employed in the code are described: A level set technique to track the position of the materials and an enrichment of the solution to allow the strain rate to be discontinuous across the interface. These techniques have low computational cost and can be used in standard desktop PCs. Examples of phase tracking with level set are presented in two and three dimensions to study slab detachment in subduction processes and Rayleigh–Taylor instabilities, respectively. The modelling of slab detachment processes includes realistic rheology with viscosity depending on temperature, pressure and strain rate; shear and adiabatic heating mechanisms; density including mineral phase changes and varying thermal conductivity. Detachment models show a first prolonged period of thermal diffusion until a fast necking of the subducting slab results in the break–off. The influence of several numerical and physical parameters on the detachment process is analyzed: The shear heating exerts a major influence accelerating the detachment process, reducing the onset time to one half and lubricating the sinking of the detached slab. The adiabatic heating term acts as a thermal stabilizer. If the mantle temperature follows an adiabatic gradient, neglecting this heating term must be included, otherwise all temperature contrasts are overestimated. As expected, the phase change at 410 km depth (olivine–spinel transition) facilitates the detachment process due to the increase in negative buoyancy. Finally, simple plume simulations are used to show how the presented numerical methodologies can be extended to three dimensions.Peer ReviewedPostprint (author’s final draft | Modelling gravitational instabilities: slab break-off and Rayleigh-Taylor diapirism | modelling gravitational instabilities: slab break-off and rayleigh-taylor diapirism | solve multiphase viscous thermo–mechanical geophysics presented. methodologies track enrichment discontinuous interface. desktop pcs. tracking slab detachment subduction rayleigh–taylor instabilities respectively. slab detachment realistic rheology viscosity adiabatic heating mineral conductivity. detachment prolonged necking subducting slab break–off. detachment heating exerts accelerating detachment reducing onset lubricating sinking detached slab. adiabatic heating acts stabilizer. mantle adiabatic neglecting heating contrasts overestimated. olivine–spinel facilitates detachment buoyancy. plume methodologies dimensions.peer reviewedpostprint author’s draft | non_dup | [] |
2634155 | 10.1007/s00024-004-2547-9 | We present a method of constructing low-dimensional nonlinear models
describing the main dynamical features of a discrete 2D cellular fault zone,
with many degrees of freedom, embedded in a 3D elastic solid. A given fault
system is characterized by a set of parameters that describe the dynamics,
rheology, property disorder, and fault geometry. Depending on the location in
the system parameter space we show that the coarse dynamics of the fault can be
confined to an attractor whose dimension is significantly smaller than the
space in which the dynamics takes place. Our strategy of system reduction is to
search for a few coherent structures that dominate the dynamics and to capture
the interaction between these coherent structures. The identification of the
basic interacting structures is obtained by applying the Proper Orthogonal
Decomposition (POD) to the surface deformations fields that accompany
strike-slip faulting accumulated over equal time intervals. We use a
feed-forward artificial neural network (ANN) architecture for the
identification of the system dynamics projected onto the subspace (model space)
spanned by the most energetic coherent structures. The ANN is trained using a
standard back-propagation algorithm to predict (map) the values of the observed
model state at a future time given the observed model state at the present
time. This ANN provides an approximate, large scale, dynamical model for the
fault.Comment: 30 pages, 12 figure | Dynamical system analysis and forecasting of deformation produced by an
earthquake fault | dynamical system analysis and forecasting of deformation produced by an earthquake fault | constructing describing fault freedom embedded elastic solid. fault rheology disorder fault geometry. coarse fault confined attractor place. coherent dominate capture coherent structures. interacting proper orthogonal decomposition deformations accompany strike slip faulting accumulated intervals. feed artificial architecture projected subspace spanned energetic coherent structures. trained propagation predict time. approximate pages | non_dup | [] |
80684103 | 10.1007/s00024-005-2691-x | The main characteristic features of stable atmospheric flows over a large mountain plateau are summarised and then compared with mesoscale and synoptic scale numerical simulation, meteorological analysis, satellite imagery, and surface observations for the cases of flows over Southern Greenland for four wind directions. The detailed features are identified using the concepts and scaling of stably stratified flow over large mountains with variations in surface roughness, elevation, and heating. For westerly and easterly winds detached jets form at the southern tip, where coastal jets converge, which propagate large distances across the ocean. Near coasts katabatic winds can combine with barrier jets and wake flows generated by synoptic winds. Note how the approach flow rises/falls over southern Greenland for easterly/westerly winds, leading in both cases to more cloud on the western side. Some conclusions are drawn about the large-scale influences of these flows; detached jets in the atmosphere; air-sea interaction; formation of low pressure systems. For accurate simulations of these flows, mesoscale models are necessary with resolutions of order of 20 km or less. © Birkhäuser Verlag, Basel, 2005 | Characteristics of stable flows over Southern Greenland | characteristics of stable flows over southern greenland | flows mountain plateau summarised mesoscale synoptic meteorological satellite imagery flows southern greenland directions. concepts stably stratified mountains roughness elevation heating. westerly easterly winds detached jets southern coastal jets converge propagate distances ocean. coasts katabatic winds combine barrier jets wake flows synoptic winds. rises falls southern greenland easterly westerly winds side. drawn influences flows detached jets atmosphere systems. flows mesoscale resolutions less. birkhã¤user verlag basel | non_dup | [] |
41146638 | 10.1007/s00024-005-2710-y | The July 17 – August 9, 2001 flank eruption of Mt. Etna was preceded and accompanied
by remarkable changes in volcanic tremor. Based on the records of stations belonging to the permanent
seismic network deployed on the volcano, we analyze amplitude and frequency content of the seismic
signal. We find considerable changes in the volcanic tremor which mark the transition to different styles of
eruptive activity, e.g., lava fountains, phreatomagmatic activity, Strombolian explosions. In particular, the
frequency content of the signal decreases from 5 Hz to 3 Hz at our reference station ETF during episodes
of lava fountains, and further decreases at about 2 Hz throughout phases of intense lava emission. The
frequency content and the ratios of the signal amplitude allow us to distinguish three seismic sources, i.e.,
the peripheral dike which fed the eruption, the reservoir which fed the lava fountains, and the central
conduit. Based on the analysis of the amplitude decay of the signal, we highlight the migration of the dike
from a depth of ca. 5 km to about 1 km between July 10 and 12. After the onset of the effusive phase, the
distribution of the amplitude decay at our stations can be interpreted as the overall result of sources
located within the first half kilometer from the surface. Although on a qualitative basis, our findings shed
some light on the complex feeding system of Mt. Etna, and integrate other volcanological and geophysical
studies which tackle the problem of magma replenishment for the July–August, 2001 flank eruption. We
conclude that volcanic tremor is fundamental in monitoring Mt. Etna, not only as a marker of the different
sources which act within the volcano edifice, but also of the diverse styles of eruptive activity | Volcanic tremor at Mt. Etna, Italy, preceding and accompanying the eruption of July-August, 2001 | volcanic tremor at mt. etna, italy, preceding and accompanying the eruption of july-august, 2001 | august flank eruption etna preceded accompanied remarkable volcanic tremor. records stations belonging permanent seismic deployed volcano analyze seismic signal. considerable volcanic tremor mark styles eruptive e.g. lava fountains phreatomagmatic strombolian explosions. station episodes lava fountains intense lava emission. distinguish seismic i.e. peripheral dike eruption reservoir lava fountains conduit. highlight migration dike onset effusive stations interpreted kilometer surface. qualitative shed feeding etna integrate volcanological geophysical tackle magma replenishment july–august flank eruption. volcanic tremor etna marker volcano edifice diverse styles eruptive | non_dup | [] |
41146536 | 10.1007/s00024-006-0039-9 | Soil CO2 flux measurements were carried out along traverses across mapped faults and
eruptive fissures on the summit and the lower East Rift Zone of Kilauea volcano. Anomalous levels of soil
degassing were found for 44 of the tectonic structures and 47 of the eruptive fissures intercepted by
the surveyed profiles. This result contrasts with what was recently observed on Mt. Etna, where most of the
surveyed faults were associated with anomalous soil degassing. The difference is probably related to the
differences in the state of activity at the time when soil gas measurements were made: Kilauea was erupting,
whereas Mt. Etna was quiescent although in a pre-eruptive stage. Unlike Mt. Etna, flank degassing on
Kilauea is restricted to the tectonic and volcanic structures directly connected to the magma reservoir
feeding the ongoing East Rift eruption or in areas of the Lower East Rift where other shallow, likely
independent reservoirs are postulated. Anomalous soil degassing was also found in areas without surface
evidence of faults, thus suggesting the possibility of previously unknown structures | Fault-controlled soil CO2 degassing and shallow magma bodies: summit and lower east rift of Kilauea volcano (Hawai’i) | fault-controlled soil co2 degassing and shallow magma bodies: summit and lower east rift of kilauea volcano (hawai’i) | traverses mapped faults eruptive fissures summit east rift kilauea volcano. anomalous degassing tectonic eruptive fissures intercepted surveyed profiles. contrasts etna surveyed faults anomalous degassing. probably kilauea erupting etna quiescent eruptive stage. unlike etna flank degassing kilauea restricted tectonic volcanic magma reservoir feeding ongoing east rift eruption east rift shallow reservoirs postulated. anomalous degassing faults unknown | non_dup | [] |
16372026 | 10.1007/s00024-007-0182-y | In this study, we propose to estimate the steric sea-level variations over a < 2-year period (April 2002 through December 2003) by combining global mean sea level (GMSL) based on Topex/ Poseidon (T/P) altimetry with time-variable geoid averaged over the oceans, as observed by the GRACE (Gravity Recovery and Climate Experiment) satellite. In effect, altimetry-derived GMSL changes results from two contributions: Steric (thermal plus salinity) effects due to sea water density change and ocean mass change due to water exchange with atmosphere and continents. On the other hand, GRACE data over the oceans provide the ocean mass change component only. The paper first discusses the corrections to apply to the GRACE data. Then the steric contribution to the GMSL is estimated using GRACE and T/P data. Comparison with available thermal expansion based on in situ hydrographic data is performed | Steric sea-level variations inferred from combined Topex/Poseidon altimetry and GRACE gravimetry | steric sea-level variations inferred from combined topex/poseidon altimetry and grace gravimetry | propose steric april december combining gmsl topex poseidon altimetry geoid averaged oceans grace recovery satellite. altimetry gmsl steric salinity ocean atmosphere continents. grace oceans ocean only. discusses grace data. steric gmsl grace data. situ hydrographic | non_dup | [] |
41149349 | 10.1007/s00024-007-0185-8. | Continuous gravity observations performed in the last few years, both at Mt. Etna and Stromboli, have prompted
the need to improve the tidal analysis in order to acquire the best corrected data for the detection of volcano
related signals. On Mt. Etna, the sites are very close to each other and the expected tidal factor differences are
negligible. It is thus useful to unify the tidal analysis results of the different data sets in a unique tidal model.
This tidal model, which can be independently confirmed by a modeling of the tidal parameters based on the elastic
response of the Earth to tidal forces and the computation of the ocean tides effects on gravity, is very useful
for the precise tidal gravity prediction required by absolute or relative discrete gravity measurements. The
change in time of the gravimeters’ sensitivity is also an important issue to be checked since it affects not only
the results of tidal analysis but also the accuracy of the observed gravity changes. Conversely, if a good tidal
model is available, the sensitivity variations can be accurately reconstructed so as to retune observed tidal
records with the synthetic tide, since the tidal parameters are assumed to be constant at a given location | Tidal gravity observations at Mt. Etna and Stromboli: results concerning the modeled and observed tidal factors | tidal gravity observations at mt. etna and stromboli: results concerning the modeled and observed tidal factors | etna stromboli prompted tidal acquire corrected volcano signals. etna tidal negligible. unify tidal tidal model. tidal independently confirmed tidal elastic earth tidal forces ocean tides precise tidal measurements. gravimeters’ checked affects tidal changes. conversely tidal accurately reconstructed retune tidal records synthetic tide tidal | non_dup | [] |
16372027 | 10.1007/s00024-007-0193-8 | Tide gauge (TG) data along the northern Mediterranean and Black Sea coasts are compared to the sea-surface height (SSH) anomaly obtained from ocean altimetry (TOPEX/Poseidon and ERS-1/2) for a period of nine years (1993–2001). The TG measures the SSH relative to the ground whereas the altimetry does so with respect to the geocentric reference frame; therefore their difference would be in principle a vertical ground motion of the TG sites, though there are different error sources for this estimate as is discussed in the paper. In this study we estimate such vertical ground motion, for each TG site, from the slope of the SSH time series of the (non-seasonal) difference between the TG record and the altimetry measurement at a point closest to the TG. Where possible, these estimates are further compared with those derived from nearby continuous Global Positioning System (GPS) data series. These results on vertical ground motion along the Mediterranean and Black Sea coasts provide useful source data for studying, contrasting, and constraining tectonic models of the region. For example, in the eastern coast of the Adriatic Sea and in the western coast of Greece, a general subsidence is observed which may be related to the Adriatic lithosphere subducting beneath the Eurasian plate along the Dinarides fault.This work is supported by the Spanish Science and Technology Ministery (Project ESP2001-4533-PE, Project ESP2005-02212), and NASA’s Physical Oceanography Program | Vertical crustal motion along the Mediterranean and Black Sea coast derived from ocean altimetry and tide gauge data | vertical crustal motion along the mediterranean and black sea coast derived from ocean altimetry and tide gauge data | tide northern mediterranean coasts anomaly ocean altimetry topex poseidon nine altimetry geocentric paper. seasonal record altimetry closest nearby positioning series. mediterranean coasts studying contrasting constraining tectonic region. eastern coast adriatic coast greece subsidence adriatic lithosphere subducting beneath eurasian plate dinarides fault.this spanish ministery nasa’s oceanography | non_dup | [] |
41154042 | 10.1007/s00024-008-0438-1 | On 6 February 2013 an Mw 8.0 subduction earthquake occurred close to Santa Cruz Islands
at the transition between the Solomon and the New Hebrides Trench. The ensuing tsunami
caused significant inundation on the closest Nendo Island. The seismic source was studied
with teleseismic broadband P waves inversion optimized with tsunami forward modeling at
DART buoys (Lay et al., 2013), and with inversion of teleseismic body and surface waves
(Hayes et al., 2014). The two studies also use different hypocenters and different planar fault
models, and found quite different slip models. In particular, Hayes et al. (2014) argued for
an aseismic slip patch SE from the hypocenter. We here develop a 3D model of the fault
surface from seismicity analysis and retrieve the tsunami source by inverting DART and tide-gauge data. Our tsunami source model features a main slip patch (peak value of ~11 m)
SE of the hypocentre, and reaching the trench. The rake direction is consistent with the
progressively more oblique plate convergence towards the Solomon trench. The tsunami
source partially overlaps the hypothesized aseismic slip area, which then might have slipped
coseismically | Source of the 6 February 2013 Mw 8.0 Santa Cruz Islands Tsunami | source of the 6 february 2013 mw 8.0 santa cruz islands tsunami | february subduction earthquake occurred santa cruz islands solomon hebrides trench. ensuing tsunami inundation closest nendo island. seismic teleseismic broadband inversion optimized tsunami dart buoys inversion teleseismic hayes hypocenters planar fault slip models. hayes argued aseismic slip patch hypocenter. fault seismicity retrieve tsunami inverting dart tide data. tsunami slip patch hypocentre reaching trench. rake progressively oblique plate solomon trench. tsunami partially overlaps hypothesized aseismic slip slipped coseismically | non_dup | [] |
52669018 | 10.1007/s00024-009-0005-4 | International audienceIn France, decades of coal and iron-ore mining have left extensive underground cavities beneath or in the vicinity of urban areas. This poses an environmental challenge for society. To ensure post-mining risk management and public safety, wherever remediation is not possible, numerous real-time microseismic monitoring systems are being installed. The objective is to detect remote rock mass fracturing processes, precursory events and acceleration phases for appropriate and timely action. Although no consistent collapse has occurred in any of the monitored areas yet, single 3-D probes record many microseismic events of very low amplitude which create difficulties in the quantitative data analysis. The development of specific quantitative processing has therefore become a major issue in our research work. For that purpose, a field experiment was carried out on six of the instrumented sites. It consisted of sequences of small blasts in mine pillars which were accurately controlled in terms of the location, orientation and energy of the explosive source. The data analysis was used to calibrate parameters (velocity model, 3-D sensor orientation, etc.) for reliable 3-D localization and to develop an empirical law to estimate the source energy from the sensor energy. This work now enables us to analyze real microseismic events with a considerably better level of accuracy and to obtain enough information and confidence to discuss these data in terms of site stability | Management of post-mining large-scale ground failures : blast swarms field experiment for calibration of permanent microseismic early-warning systems | management of post-mining large-scale ground failures : blast swarms field experiment for calibration of permanent microseismic early-warning systems | audiencein decades coal iron mining extensive underground cavities beneath vicinity areas. poses challenge society. ensure mining wherever remediation numerous microseismic installed. detect remote rock fracturing precursory acceleration timely action. collapse occurred monitored probes record microseismic create difficulties analysis. work. instrumented sites. consisted blasts mine pillars accurately explosive source. calibrate sensor etc. reliable localization sensor energy. enables analyze microseismic considerably confidence | non_dup | [] |
41150561 | 10.1007/s00024-009-0020-5 | The South Atlantic magnetic Anomaly (SAA) is an important feature of the present geomagnetic field. In this paper we model the space–time evolution of this anomaly over the past 400 years in terms of the resultant between a decrease of a global axial dipole and an increase of a virtual local monopole source. Certain characteristics of this evolution are investigated and some considerations
are made in the light of a possible special state of the global geomagnetic field dynamical regime. Among the possible
speculations, one is made regarding the topography of the coremantle boundary (CMB) and its possible aspect beneath the SAA
region in terms of simple sinusoidal undulations met by the monopole source during its centennial motion | Equivalent Monopole Source of the Geomagnetic South Atlantic Anomaly | equivalent monopole source of the geomagnetic south atlantic anomaly | atlantic anomaly geomagnetic field. space–time anomaly resultant axial dipole virtual monopole source. considerations geomagnetic regime. speculations topography coremantle aspect beneath sinusoidal undulations monopole centennial | non_dup | [] |
41151037 | 10.1007/s00024-010-0065-5. | We present a five-year, time-independent, earthquake-forecast model for earthquake magnitudes of 5.0 and greater in Italy using spatially smoothed seismicity data. The model is called HAZGRIDX, and it was developed based on the assumption that future earthquakes will occur near locations of historical earthquakes; it does not take into account any information from tectonic, geological, or geodetic data. Thus HAZGRIDX is based on observed earthquake occurrence from seismicity data, without considering any physical model. In the present study, we calculate earthquake rates on a spatial grid platform using two declustered catalogs: 1) the Parametric catalog of Italian earthquakes (Catalogo Parametrico dei Terremoti Italiani, CPTI04) that contains the larger earthquakes from MW 7.0 since 1100; and 2) the Italian seismicity catalogue (Catalogo della Sismicità Italiana, CSI 1.1) that contains the small earthquakes down to ML 1.0, with a maximum of ML 5.9, over the past 22 years (1981-2003). The model assumes that earthquake magnitudes follow the Gutenberg-Richter law, with a uniform b-value. The forecast rates are presented in terms of the expected numbers of ML>5.0 events per year for each grid cell of about 10 km × 10 km. The final map is derived by averaging the earthquake potentials that come from these two different catalogs: CPTI04 and CSI 1.1. We also describe the earthquake occurrences in terms of probabilities of occurrence of one event within a specified magnitude bin, DM0.1, in a five year time period. HAZGRIDX is one of several forecasting models, scaled to five and ten years, that have been submitted to the Collaboratory for the Study of Earthquake Probability (CSEP) forecasting center in ETH, Zurich, to be tested for Italy | HAZGRIDX: earthquake forecasting model for ML ≥ 5.0 earthquakes in Italy based on spatially smoothed seismicity | hazgridx: earthquake forecasting model for ml ≥ 5.0 earthquakes in italy based on spatially smoothed seismicity | earthquake forecast earthquake magnitudes spatially smoothed seismicity data. hazgridx earthquakes locations historical earthquakes tectonic geological geodetic data. hazgridx earthquake occurrence seismicity model. earthquake platform declustered catalogs parametric catalog italian earthquakes catalogo parametrico terremoti italiani cpti earthquakes italian seismicity catalogue catalogo della sismicità italiana earthquakes assumes earthquake magnitudes gutenberg richter value. forecast averaging earthquake potentials come catalogs cpti earthquake occurrences probabilities occurrence specified period. hazgridx forecasting scaled submitted collaboratory earthquake csep forecasting zurich | non_dup | [] |
36044947 | 10.1007/s00024-010-0091-3 | In weather forecasting, current and past observational data are routinely assimilated into numerical simulations to produce ensemble forecasts of future events in a process termed “model steering”. Here we describe a similar approach that is motivated by analyses of previous forecasts of the Working Group on California Earthquake Probabilities (WGCEP). Our approach is adapted to the problem of earthquake forecasting using topologically realistic numerical simulations for the strike-slip fault system in California. By systematically comparing simulation data to observed paleoseismic data, a series of spatial probability density functions (PDFs) can be computed that describe the probable locations of future large earthquakes. We develop this approach and show examples of PDFs associated with magnitude M > 6.5 and M > 7.0 earthquakes in California.Peer reviewe | Space- and time- dependent probabilities for earthquake fault systems from numerical simulations: feasibility study and first results | space- and time- dependent probabilities for earthquake fault systems from numerical simulations: feasibility study and first results | weather forecasting observational routinely assimilated ensemble forecasts termed “model steering”. motivated forecasts california earthquake probabilities wgcep adapted earthquake forecasting topologically realistic strike slip fault california. systematically paleoseismic pdfs probable locations earthquakes. pdfs earthquakes california.peer reviewe | non_dup | [] |
36073379 | 10.1007/s00024-010-0206-x | 17 pages, 9 figuresThree thousand kilometres of multichannel (MCS) and wide-angle seismic profiles, gravity and magnetic, multibeam bathymetry and backscatter data were recorded in the offshore area of the west coast of Mexico and the Gulf of California during the spring 1996 (CORTES survey). The seismic images obtained off Puerto Vallarta, Mexico, in the Jalisco subduction zone extend from the oceanic domain up to the continental shelf, and significantly improve the knowledge of the internal crustal structure of the subduction zone between the Rivera and North American (NA) Plates. Analyzing the crustal images, we differentiate: (1) An oceanic domain with an important variation in sediment thickness ranging from 2.5 to 1 km southwards; (2) an accretionary prism comprised of highly deformed sediments, extending for a maximum width of 15 km; (3) a deformed forearc basin domain which is 25 km wide in the northern section, and is not seen towards the south where the continental slope connects directly with the accretionary prism and trench, thus suggesting a different deformational process; and (4) a continental domain consisting of a continental slope and a mid slope terrace, with a bottom simulating reflector (BSR) identified in the first second of the MCS profiles. The existence of a developed accretionary prism suggests a subduction–accretion type tectonic regime. Detailed analysis of the seismic reflection data in the oceanic domain reveals high amplitude reflections at around 6 s [two way travel time (twtt)] that clearly define the subduction plane. At 2 s (twtt) depth we identify a strong reflection which we interpret as the Moho discontinuity. We have measured a mean dip angle of 7° ± 1° at the subduction zone where the Rivera Plate begins to subduct, with the dip angle gently increasing towards the south. The oceanic crust has a mean crustal thickness of 6.0–6.5 km. We also find evidence indicating that the Rivera Plate possibly subducts at very low angles beneath the Tres Marias Islands.Funding is from the Spanish National Research\ud
Project (ANT94-0182-C02-01/02). Additional funding comes from INSU-France, ORSTOM-IRD,\ud
France bilateral cooperation (HF1997-077), and CSIC/CONACYT 0894PT, the Secretaría de Marina of Mexico, CICESE project 644107 and by CIRIT (Project 1995SGR00438).R. Bartolome acknowledges the financial support of the Spanish Ministry of Science and Innovation (Ramon y Cajal program).Peer reviewe | Imaging the Seismic Crustal Structure of the Western Mexican Margin between 19ºN and 21ºN | imaging the seismic crustal structure of the western mexican margin between 19ºn and 21ºn | pages figuresthree thousand kilometres multichannel seismic multibeam bathymetry backscatter offshore west coast mexico gulf california spring cortes seismic puerto vallarta mexico jalisco subduction extend oceanic continental shelf crustal subduction rivera plates. analyzing crustal differentiate oceanic sediment ranging southwards accretionary prism comprised deformed sediments extending deformed forearc basin northern continental connects accretionary prism trench deformational continental consisting continental terrace simulating reflector profiles. accretionary prism subduction–accretion tectonic regime. seismic reflection oceanic reveals reflections travel twtt subduction plane. twtt reflection interpret moho discontinuity. subduction rivera plate begins subduct gently south. oceanic crust crustal rivera plate possibly subducts angles beneath tres marias islands.funding spanish funding comes insu orstom bilateral cooperation csic conacyt secretaría marina mexico cicese cirit bartolome acknowledges spanish ministry innovation ramon cajal .peer reviewe | non_dup | [] |
41151431 | 10.1007/s00024-011-0297-z. | Fumarole temperatures are the ultimate results of many processes that
are encountered by deep fluids during their passage to the surface. Here,
the time variations of high-temperature fumaroles acquired by
continuous monitoring are presented, to show the effects of the forces that
act on the system. Data acquired by continuous monitoring of fumaroles
and the time relationships with the different parameters related to the
activity of the volcanic system are discussed. From 1998 to 2010, the
temperature and compositional changes of fumarolic gases were
monitored at the same time as variations in the number of volcanoseismic
events, which indicate frequent variations of energy release (heat
and mass flow, and seismic strain release). Geochemical modeling applied
to the volcanic system of Vulcano Island suggests that the overall
expansion of magmatic gas through the fractured system is an almost
iso-enthalpic process at depth, which shifts to an adiabatic process at
shallow depth, where the rock permeability increases. Thus, the time
variations of the fumarole temperatures reflect various physical
variations of the system that can either occur at depth or close to the
surface. The temperature monitoring performed in the fumarolic area of
La Fossa Cone showed short-term effects related to rain events, and
negligible effects related to other external agents (ambient temperature
and atmospheric pressure variations). At the same time, the long-term
monitoring highlighted some mean-term and long-term variations. These
last are the main characters observed in the time-series, and they both
appear to be related to endogenous forces that perturb the equilibrium of
this complex geochemical system | Long-term variations of fumarole temperatures on Vulcano Island (Italy) | long-term variations of fumarole temperatures on vulcano island (italy) | fumarole ultimate encountered fluids passage surface. fumaroles acquired forces system. acquired fumaroles volcanic discussed. compositional fumarolic gases monitored volcanoseismic frequent seismic geochemical volcanic vulcano island magmatic fractured enthalpic shifts adiabatic shallow rock permeability increases. fumarole reflect surface. fumarolic fossa cone rain negligible ambient highlighted variations. characters endogenous forces perturb geochemical | non_dup | [] |
52729854 | 10.1007/s00024-011-0320-4 | International audienceThe coupled mechanics of fluid-filled granular media controls the physics of many Earth systems, for example saturated soils, fault gouge, and landslide shear zones. It is well established that when the pore fluid pressure rises, the shear resistance of fluid-filled granular systems decreases, and, as a result, catastrophic events such as soil liquefaction, earthquakes, and accelerating landslides may be triggered. Alternatively, when the pore pressure drops, the shear resistance of these geosystems increases. Despite the great importance of the coupled mechanics of grain-fluid systems, the basic physics that controls this coupling is far from understood. Fundamental questions that must be addressed include: what are the processes that control pore fluid pressurization and depressurization in response to deformation of the granular skeleton? and how do variations of pore pressure affect the mechanical strength of the grains skeleton? To answer these questions, a formulation for the pore fluid pressure and flow has been developed from mass and momentum conservation, and is coupled with a granular dynamics algorithm that solves the grain dynamics, to form a fully coupled model. The pore fluid formulation reveals that the evolution of pore pressure obeys viscoelastic rheology in response to pore space variations. Under undrained conditions elastic-like behavior dominates and leads to a linear relationship between pore pressure and overall volumetric strain. Viscous-like behavior dominates under well-drained conditions and leads to a linear relationship between pore pressure and volumetric strain rate. Numerical simulations reveal the possibility of liquefaction under drained and initially over-compacted conditions, which were often believed to be resistant to liquefaction. Under such conditions liquefaction occurs during short compactive phases that punctuate the overall dilative trend. In addition, the previously recognized generation of elevated pore pressure under undrained compactive conditions is observed. Simulations also show that during liquefaction events stress chains are detached, the external load becomes completely supported by the pressurized pore fluid, and shear resistance vanishes | The mechanical coupling of fluid-filled granular material under shear | the mechanical coupling of fluid-filled granular material under shear | audiencethe mechanics filled granular earth saturated soils fault gouge landslide zones. pore rises filled granular catastrophic liquefaction earthquakes accelerating landslides triggered. alternatively pore drops geosystems increases. great mechanics grain understood. addressed pore pressurization depressurization deformation granular skeleton pore grains skeleton answer formulation pore conservation granular solves grain model. pore formulation reveals pore obeys viscoelastic rheology pore variations. undrained elastic dominates pore volumetric strain. viscous dominates drained pore volumetric rate. reveal liquefaction drained initially compacted believed resistant liquefaction. liquefaction compactive punctuate dilative trend. recognized elevated pore undrained compactive observed. liquefaction chains detached pressurized pore vanishes | non_dup | [] |
41152015 | 10.1007/s00024-011-0390-3 | The effects of surface geology on ground motion
provide an important tool in seismic hazard studies. It is well
known that the presence of soft sediments can cause amplification
of the ground motion at the surface, particularly when there is a
sharp impedance contrast at shallow depth. The town of Avellino is
located in an area characterised by high seismicity in Italy, about
30 km from the epicentre of the 23 November 1980, Irpinia
earthquake (M = 6.9). No earthquake recordings are available in
the area. The local geology is characterised by strong heterogeneity,
with impedance contrasts at depth. We present the results
from seismic noise measurements carried out in the urban area of
Avellino to evaluate the effects of local geology on the seismic
ground motion. We computed the horizontal-to-vertical (H/V)
noise spectral ratios at 16 selected sites in this urban area for which
drilling data are available within the first 40 m of depth. A Rayleigh
wave inversion technique using the peak frequencies of the
noise H/V spectral ratios is then presented for estimating Vs
models, assuming that the thicknesses of the shallow soil layers are
known. The results show a good correspondence between experimental
and theoretical peak frequencies, which are interpreted in
terms of sediment resonance. For one site, which is characterised
by a broad peak in the horizontal-to-vertical spectral-ratio curve,
simple one-dimensional modelling is not representative of the
resonance effects. Consistent variations in peak amplitudes are seen
among the sites. A site classification based on shear-wave velocity
characteristics, in terms of Vs30, cannot explain these data. The
differences observed are better correlated to the impedance contrast
between the sediments and basement. A more detailed investigation
of the physical parameters of the subsoil structure, together with
earthquake data, are desirable for future research, to confirm these
data in terms of site response | Effects of Surface Geology on Seismic Ground Motion Deduced from Ambient-Noise Measurements in the Town of Avellino, Irpinia Region (Italy) | effects of surface geology on seismic ground motion deduced from ambient-noise measurements in the town of avellino, irpinia region (italy) | geology seismic hazard studies. sediments amplification sharp impedance shallow depth. town avellino characterised seismicity epicentre november irpinia earthquake earthquake recordings area. geology characterised heterogeneity impedance contrasts depth. seismic avellino geology seismic motion. drilling depth. rayleigh inversion estimating thicknesses shallow known. correspondence interpreted sediment resonance. characterised broad effects. amplitudes sites. data. impedance sediments basement. subsoil earthquake desirable confirm | non_dup | [] |
28943339 | 10.1007/s00024-011-0438-4 | The 2004 Indian Ocean tsunami was observed by two satellites, close in space and time, that traversed the Indian ocean two hours after the Sumatra-Andaman earthquake, but which observed different tsunami lead wave morphologies. The earlier satellite, Jason-1, recorded a lead wave with two peaks of similar amplitude and wavelength, while the later satellite, TOPEX/Poseidon, recorded a lead wave with only one longer wavelength uplift. To resolve this disparity, we examine the travel paths of long wavelength waves over the seafloor bathymetry. Waves traveling from the margin will traverse significantly different paths to arrive at the two satellite transects. The result is that the satellites are sensitive to different parts of the margin; Jason-1 is highly sensitive to the margin in the area of the epicenter, while TOPEX is sensitive to a more northerly section. By developing solutions of the ocean gravity wave equations, accounting for dispersion, we show that the double peak of the Jason-1 satellite observations are consistent with coseismic rupture of a splay fault of limited along-strike extent, located north of Simeulue Island. The doubly peaked morphology can be reproduced with co-activation of the subduction zone interface and the splay fault, which creates a seafloor uplift pattern with two distinct areas of uplift. The Jason-1 satellite is sensitive to a splay fault in this portion of the margin, whereas the TOPEX satellite would not be significantly affected by this uplift pattern. By back-projecting satellite observation points to the margin, we constrain the location of the proposed splay fault and find that it correlates with a bathymetric high. The aftershock locations, uplift of corals on Simeulue Island and a fault scarp on Pulau Salaut Besar are also consistent with the activation of a splay fault in the area delimited by the back-projection. Our work also shows that it is critical to fully capture gravity wave dispersion in order to represent features of the lead wave profile that may not be as well characterized by the shallow water (long-wavelength) model. It is also necessary to account for dispersion so as to precisely assess wavefront travel times; this leads us to conclude that the rupture must have reached very near to the trench and propagated with an updip rupture velocity of order 2.0 km/s or more.Earth and Planetary SciencesEngineering and Applied Science | Tsunami Wave Analysis and Possibility of Splay Fault Rupture During the 2004 Indian Ocean Earthquake | tsunami wave analysis and possibility of splay fault rupture during the 2004 indian ocean earthquake | indian ocean tsunami satellites traversed indian ocean sumatra andaman earthquake tsunami morphologies. satellite jason satellite topex poseidon uplift. resolve disparity examine travel paths seafloor bathymetry. traveling margin traverse paths arrive satellite transects. satellites margin jason margin epicenter topex northerly section. ocean accounting jason satellite coseismic rupture splay fault strike simeulue island. doubly peaked morphology reproduced subduction splay fault creates seafloor uplift uplift. jason satellite splay fault portion margin topex satellite uplift pattern. projecting satellite margin constrain splay fault correlates bathymetric high. aftershock locations uplift corals simeulue island fault scarp pulau salaut besar splay fault delimited projection. capture shallow model. precisely wavefront travel rupture reached trench propagated updip rupture more.earth planetary sciencesengineering | non_dup | [] |
77618119 | 10.1007/s00024-012-0552-y | A simple 1D kinematic cloud model coupled to a two-moment bulk microphysics scheme is used to perform quasi-idealized simulations of snow, with a prescribed upper boundary snow field based on observed radar reflectivity and temperature, falling into a low-level melting layer. The model realistically simulates the formation of a nearly isothermal layer below the melting level, the surface precipitation rate, and the phase transition from liquid to solid, consistent with observations for this case. A series of test runs is performed to examine the sensitivity of modeling the timing and duration of the phase transition period to details of specific parameterization aspects related to snow in the microphysics scheme. The sensitivity tests include varying the number of prognostic moments, the mass–diameter relation, the fall velocity–diameter relation, the treatment of aggregation, and the lower limit for the slope of the size distribution. It is shown that the simulated transition period, for such a case with the initial melting level being close to the surface, can be quite sensitive to model parameters specified within realistic ranges and/or ranges within our physical understanding | Modeling the Phase Transition Associated with Melting Snow in a 1D Kinematic Framework: Sensitivity to the Microphysics | modeling the phase transition associated with melting snow in a 1d kinematic framework: sensitivity to the microphysics | kinematic moment microphysics quasi idealized snow prescribed snow radar reflectivity falling melting layer. realistically simulates nearly isothermal melting precipitation case. runs examine timing parameterization snow microphysics scheme. prognostic moments mass–diameter fall velocity–diameter aggregation distribution. melting specified realistic ranges ranges | non_dup | [] |
39299395 | 10.1007/s00024-012-0571-8 | The failure of brittle materials, for example glasses and rock masses, is commonly observed to be discontinuous. It is, however, difficult to simulate these phenomena by use of conventional numerical simulation methods, for example the finite difference method or the finite element method, because of the presence of computational grids or elements artificially introduced before the simulation. It is, therefore, important for research on such discontinuous failures in science and engineering to analyze the phenomena seamlessly. This study deals with the coupled simulation of elastic wave propagation and failure phenomena by use of a moving particle semi-implicit (MPS) method. It is simple to model the objects of analysis because no grid or lattice structure is necessary. In addition, lack of a grid or lattice structure makes it simple to simulate large deformations and failure phenomena at the same time. We first compare analytical and MPS solutions by use of Lamb’s problem with different offset distances, material properties, and source frequencies. Our results show that analytical and numerical seismograms are in good agreement with each other for 20 particles in a minimum wavelength. Finally, we focus our attention on the Hopkinson effect as an example of failure induced by elastic wave propagation. In the application of the MPS, the algorithm is basically the same as in the previous calculation except for the introduction of a failure criterion. The failure criterion applied in this study is that particle connectivity must be disconnected when the distance between the particles exceeds a failure threshold. We applied the developed algorithm to a suspended specimen that was modeled as a long bar consisting of thousands of particles. A compressional wave in the bar is generated by an abrupt pressure change on one edge. The compressional wave propagates along the interior of the specimen and is visualized clearly. At the other end of the bar, the spalling of the bar is reproduced numerically, and a broken piece of the bar is formed and falls away from the main body of the bar. Consequently, these results show that the MPS method effectively reproduces wave propagation and failure phenomena at the same time | Coupled Simulation of Seismic Wave Propagation and Failure Phenomena by Use of an MPS Method | coupled simulation of seismic wave propagation and failure phenomena by use of an mps method | brittle glasses rock commonly discontinuous. simulate phenomena grids artificially simulation. discontinuous failures analyze phenomena seamlessly. deals elastic propagation phenomena moving implicit method. necessary. simulate deformations phenomena time. lamb’s offset distances frequencies. seismograms wavelength. hopkinson elastic propagation. basically criterion. criterion connectivity disconnected exceeds threshold. suspended specimen modeled consisting thousands particles. compressional abrupt edge. compressional propagates interior specimen visualized clearly. spalling reproduced numerically broken piece falls away bar. effectively reproduces propagation phenomena | non_dup | [] |
52725824 | 10.1007/s00024-012-0637-7 | International audienceMany natural examples of complex joint and vein networks in layered sedimentary rocks are hydro-fractures that form by a combination of pore fluid overpressure and tectonic stresses. In this paper, a two-dimensional hybrid hydro-mechanical formulation is proposed to model the dynamic development of natural hydrofractures. The numerical scheme combines a Discrete Element Model (DEM) framework that represents a porous solid medium with a supplementary Darcy based pore-pressure diffusion as continuum description for the fluid. This combination yields a porosity controlled coupling between an evolving fracture network and the associated hydraulic field. The model is tested on some basic cases of hydro-driven fracturing commonly found in nature i.e., fracturing due to local fluid overpressure in rocks subjected to hydrostatic and nonhydrostatic tectonic loadings. In our models we find that seepage forces created by hydraulic pressure gradients together with poroelastic feedback upon discrete fracturing play a significant role in subsurface rock deformation. These forces manipulate the growth and geometry of hydrofractures in addition to tectonic stresses and the mechanical properties of the porous rocks. Our results show characteristic failure patterns that reflect different tectonic and lithological conditions and are qualitatively consistent with existing analogue and numerical studies as well as field observations. The applied scheme is numerically efficient, can be applied at various scales and is computational cost effective with the least involvement of sophisticated mathematical computation of hydrodynamic flow between the solid grains | Dynamic Development of Hydrofracture | dynamic development of hydrofracture | audiencemany vein layered sedimentary rocks hydro fractures pore overpressure tectonic stresses. hybrid hydro formulation hydrofractures. combines porous supplementary darcy pore continuum fluid. porosity evolving fracture hydraulic field. hydro fracturing commonly i.e. fracturing overpressure rocks subjected hydrostatic nonhydrostatic tectonic loadings. seepage forces created hydraulic gradients poroelastic fracturing subsurface rock deformation. forces manipulate hydrofractures tectonic stresses porous rocks. reflect tectonic lithological qualitatively analogue observations. numerically involvement sophisticated mathematical hydrodynamic grains | non_dup | [] |
24994018 | 10.1007/s00024-014-0825-8 | Wet-dry interface which appreciably increases accuracy of tsunami simulations
with the MOST model (Method of Splitting Tsunamis, adapted by the NOAA for
tsunami forecasting operations) is highlighted here with a few comparative
simulations. The new solution, termed Cliffs, exceeds all MOST versions in
accuracy of computing later waves. This is demonstrated with simulation of the
Tohoku-2011 tsunami to Monterey Bay, CA, and into fiords, bays, and inlets of
southeastern Alaska, followed by comparison with tide gage records.Comment: 6 pages, 4 figures; highlights one aspect of a paper in the proces | Comparative simulations of the 2011 Tohoku tsunami with MOST and Cliffs | comparative simulations of the 2011 tohoku tsunami with most and cliffs | appreciably tsunami splitting tsunamis adapted noaa tsunami forecasting operations highlighted comparative simulations. termed cliffs exceeds versions waves. tohoku tsunami monterey fiords bays inlets southeastern alaska tide gage pages highlights aspect proces | non_dup | [] |
41153321 | 10.1007/s00024-014-0873-0 | We present a systematic and updated overview of a seismotectonic model for the Po
Plain (northern Italy). This flat and apparently quiet tectonic domain is in fact rather
active as it comprises the shortened foreland and foredeep of both the Southern Alps
and the Northern Apennines. Assessing its seismic hazard is crucial due to the
concentration of population, industrial activities and critical infrastructures, but it is also
complicated because a) the region is geologically very diverse, and b) nearly all
potential seismogenic faults are buried beneath a thick blanket of Pliocene-Pleistocene
sediments, and hence can be investigated only indirectly.
Identifying and parameterizing the potential seismogenic faults of the Po Plain requires
proper consideration of their depth, geometry, kinematics, earthquake potential and
location with respect to the two confronting orogens. To this end we subdivided them
into four main homogeneous groups. Over the past 15 years we developed new
strategies for coping with this diversity, resorting to different data and modeling
approaches as required by each individual fault group.
The most significant faults occur beneath the thrust fronts of the Ferrara-Romagna and
Emilia arcs, which correspond to the most advanced and buried portions of the
Northern Apennines and were the locus of the destructive May 2012 earthquake
sequence. The largest known Po Plain earthquake, however, occurred on an elusive
reactivated fault cutting the Alpine foreland south of Verona. Significant earthquakes
are expected to be generated also by a set of transverse structures segmenting the
thrust system, and by the deeper ramps of the Apennines thrusts.
The new dataset is intended to be included in the next version of the Database of
Seismogenic Sources (DISS; http://diss.rm.ingv.it/diss/, version 3.2.0, developed and
maintained by INGV) to improve completeness of potential sources for seismic hazard
assessment | The seismotectonics of the Po Plain (northern Italy): tectonic diversity in a blind faulting domain | the seismotectonics of the po plain (northern italy): tectonic diversity in a blind faulting domain | updated overview seismotectonic plain northern apparently quiet tectonic comprises shortened foreland foredeep southern alps northern apennines. assessing seismic hazard crucial industrial infrastructures complicated geologically diverse nearly seismogenic faults buried beneath thick blanket pliocene pleistocene sediments indirectly. identifying parameterizing seismogenic faults plain proper consideration kinematics earthquake confronting orogens. subdivided homogeneous groups. coping diversity resorting fault group. faults beneath thrust fronts ferrara romagna emilia arcs advanced buried portions northern apennines locus destructive earthquake sequence. plain earthquake occurred elusive reactivated fault cutting alpine foreland verona. earthquakes segmenting thrust deeper ramps apennines thrusts. dataset intended seismogenic diss maintained ingv completeness seismic hazard | non_dup | [] |
78063693 | 10.1007/s00024-014-0874-z | “Dynamic complexity” is a phenomenon observed for a nonlinearly interacting system within which multitudes of different sizes of large scale coherent structures emerge, resulting in a globally nonlinear stochastic behavior vastly different from that which could be surmised from the underlying equations of interaction. A characteristic of such nonlinear, complex phenomena is the appearance of intermittent fluctuating events with the mixing and distribution of correlated structures on all scales. We briefly review here a relatively recent method, ROMA (rank-ordered multifractal analysis), explicitly developed for analysis of the intricate details of the distribution and scaling of such types of intermittent structure. This method is then used for analysis of selected examples related to the dynamic plasmas of the cusp region of the Earth’s magnetosphere, velocity fluctuations of classical hydrodynamic turbulence, and the distribution of the structures of the cosmic gas obtained by use of large-scale, moving mesh simulations. Differences and similarities of the analyzed results among these complex systems will be contrasted and highlighted. The first two examples have direct relevance to the Earth’s environment (i.e., geoscience) and are summaries of previously reported findings. The third example, although involving phenomena with much larger spatiotemporal scales, with its highly compressible turbulent behavior and the unique simulation technique employed in generating the data, provides direct motivation for applying such analysis to studies of similar multifractal processes in extreme environments of near-Earth surroundings. These new results are both exciting and intriguing.National Science Foundation (U.S.)Seventh Framework Programme (European Commission) (FP7/2007-2013 Grant Agreement 313038/STORM | Complexity Phenomena and ROMA of the Earth’s Magnetospheric Cusp, Hydrodynamic Turbulence, and the Cosmic Web | complexity phenomena and roma of the earth’s magnetospheric cusp, hydrodynamic turbulence, and the cosmic web | “dynamic complexity” phenomenon nonlinearly interacting multitudes sizes coherent emerge globally stochastic vastly surmised interaction. phenomena appearance intermittent fluctuating scales. briefly roma ordered multifractal explicitly intricate intermittent structure. plasmas cusp earth’s magnetosphere hydrodynamic turbulence cosmic moving mesh simulations. similarities contrasted highlighted. relevance earth’s i.e. geoscience summaries findings. involving phenomena spatiotemporal compressible turbulent generating motivation multifractal extreme environments earth surroundings. exciting intriguing.national foundation u.s. seventh programme commission storm | non_dup | [] |
32326770 | 10.1007/s00024-014-0879-7 | A suitable knowledge of the orientation and motion of the Earth in space is a common need in various fields. That knowledge has been ever necessary to carry out astronomical observations, but with the advent of the space age, it became essential for making observations of satellites and predicting and determining their orbits, and for observing the Earth from space as well. Given the relevant role it plays in Space Geodesy, Earth rotation is considered as one of the three pillars of Geodesy, the other two being geometry and gravity. Besides, research on Earth rotation has fostered advances in many fields, such as Mathematics, Astronomy and Geophysics, for centuries. One remarkable feature of the problem is in the extreme requirements of accuracy that must be fulfilled in the near future, about a millimetre on the tangent plane to the planet surface, roughly speaking. That challenges all of the theories that have been devised and used to-date; the paper makes a short review of some of the most relevant methods, which can be envisaged as milestones in Earth rotation research, emphasizing the Hamiltonian approach developed by the authors. Some contemporary problems are presented, as well as the main lines of future research prospected by the International Astronomical Union/International Association of Geodesy Joint Working Group on Theory of Earth Rotation, created in 2013.This work has been partially supported by the Spanish government under Grants AYA2010-22039-C02-01 and AYA2010-22039-C02-02 from Ministerio de Economía y Competitividad (MINECO), the University of Alicante under Grant GRE11-08 and the Generalitat Valenciana, Grant GV/2014/072 | Earth’s Rotation: A Challenging Problem in Mathematics and Physics | earth’s rotation: a challenging problem in mathematics and physics | earth fields. ever carry astronomical advent became satellites predicting determining orbits observing earth well. plays geodesy earth pillars geodesy gravity. besides earth fostered advances mathematics astronomy geophysics centuries. remarkable extreme fulfilled millimetre tangent planet roughly speaking. challenges devised envisaged milestones earth emphasizing authors. contemporary prospected astronomical union geodesy earth created .this partially spanish grants ministerio economía competitividad mineco alicante generalitat valenciana | non_dup | [] |
25012432 | 10.1007/s00024-014-0889-5 | In this paper we study the motion of a fluid with several dispersed particles
whose concentration is very small (smaller than $10^{-3}$), with possible
applications to problems coming from geophysics, meteorology, and oceanography.
We consider a very dilute suspension of heavy particles in a
quasi-incompressible fluid (low Mach number). In our case the Stokes number is
small and --as pointed out in the theory of multiphase turbulence-- we can use
an Eulerian model instead of a Lagrangian one. The assumption of low
concentration allows us to disregard particle--particle interactions, but we
take into account the effect of particles on the fluid (two-way coupling). In
this way we can study the physical effect of particle inertia (and not only
passive tracers), with a model similar to the Boussinesq equations. The
resulting model is used in both direct numerical simulations and large eddy
simulations of a dam-break (lock-exchange) problem, which is a well-known
academic test case. Keywords: Dilute suspensions, Eulerian models, direct and
large eddy simulations, slightly compressible flows, dam-break (lock-exchange)
problem.Comment: 28 pages, 7 figure | Disperse two-phase flows, with applications to geophysical problems | disperse two-phase flows, with applications to geophysical problems | dispersed coming geophysics meteorology oceanography. dilute suspension quasi incompressible mach stokes pointed multiphase turbulence eulerian lagrangian one. disregard inertia passive tracers boussinesq equations. eddy break lock academic case. keywords dilute suspensions eulerian eddy compressible flows break lock pages | non_dup | [] |
41153625 | 10.1007/s00024-014-0912-x | Geosytemics is a way to see and study the Earth in its wholeness, together with the eventual couplings among the subsystems composing our planet. This paper will provide this view for the
Earth’s magnetic field, reviewing most of the results obtained in our recent works. The main tools used by geosystemics are some nonlinear quantities, such as some kinds of entropy. Through them, it is possible to: a) establish the chaoticity and ergodicity of the recent geomagnetic field in a direct
and simple way; b) indentify the most extreme events in its history, as the most rapid and the slowest ones, i.e. jerks and polarity changes (reversals or excursions). In particular, regarding the latter phenomena, with the help of these entropic concepts and together with the use of the theory of
critical transitions, some clues can be given for a possible imminent change of the geomagnetic field dynamical regime | Geosystemics: a systemic view of the Earth’s magnetic field and possibilities for an imminent geomagnetic transition | geosystemics: a systemic view of the earth’s magnetic field and possibilities for an imminent geomagnetic transition | geosytemics earth wholeness eventual couplings subsystems composing planet. earth’s reviewing works. geosystemics quantities kinds entropy. establish chaoticity ergodicity geomagnetic indentify extreme slowest i.e. jerks polarity reversals excursions phenomena entropic concepts clues imminent geomagnetic | non_dup | [] |
33176070 | 10.1007/s00024-014-0916-6 | The Canary Islands are mostly characterized by diffuse and scattered volcanism affecting a large area, with only one active stratovolcano, the Teide?Pico Viejo complex (Tenerife). More than 2 million people live and work in the 7,447 km2 of the archipelago, resulting in an average population density three times greater than the rest of Spain. This fact, together with the growth of exposure during the past 40 years, increases volcanic risk with respect previous eruptions, as witnessed during the recent 2011?2012 El Hierro submarine eruption. Therefore, in addition to purely scientific reasons there are economic and population-security reasons for developing and maintaining an efficient volcano monitoring system. In this scenario geodetic monitoring represents an important part of the monitoring system. We describe volcano geodetic monitoring research carried out in the Canary Islands and the results obtained. We consider for each epoch the two main existing constraints: the level of volcanic activity in the archipelago, and the limitations of the techniques available at the time. Theoretical and observational aspects are considered, as well as the implications for operational volcano surveillance. Current challenges of and future perspectives in geodetic volcano monitoring in the Canaries are also presented | An Overview of Geodetic Volcano Research in the Canary Islands | an overview of geodetic volcano research in the canary islands | canary islands mostly diffuse scattered volcanism affecting stratovolcano teide pico viejo tenerife million live archipelago spain. volcanic eruptions witnessed hierro submarine eruption. purely reasons security reasons maintaining volcano system. geodetic system. volcano geodetic canary islands obtained. epoch volcanic archipelago limitations time. observational operational volcano surveillance. challenges perspectives geodetic volcano canaries | non_dup | [] |
33104078 | 10.1007/s00024-014-0919-3 | The study of the temporal evolution of the dipole moment variations is a forefront research topic in Earth sciences. It constrains geodynamo simulations and is used to correct cosmogenic isotope production, which is evidence of past solar activity, and it is used to study possible correlations between the geomagnetic field and the climate. In this work, we have analysed the main error sources in the geomagnetic dipole moment computation from palaeomagnetic data: the influence of the non-dipole terms in the average approach, the inhomogeneous distribution of the current palaeomagnetic database, and the averaging procedure used to obtain the evolution of the dipole moment. To evaluate and quantify these effects, we have used synthetic data from a global model based on instrumental and satellite data, the International Geomagnetic Reference Field: 11th generation. Results indicate that the non-dipole terms contribute on a global scale of < 6 % in the averaged dipole moment, whereas the regional non-dipole contribution can show deviations of up to 35 % in some regions such as Oceania, and different temporal trends with respect to the global dipole moment evolution in other ones, such as Europe and Asia. A regional weighting scheme seems the best option to mitigate these effects in the dipole moment average approach. But when directional and intensity palaeomagnetic information is available on a global scale, and in spite of the inhomogeneity of the database, global modelling presents more reliable values of the geomagnetic dipole moment | Non-dipole and regional effects on the geomagnetic dipole moment estimation | non-dipole and regional effects on the geomagnetic dipole moment estimation | dipole moment forefront topic earth sciences. constrains geodynamo cosmogenic isotope geomagnetic climate. analysed geomagnetic dipole moment palaeomagnetic dipole inhomogeneous palaeomagnetic averaging dipole moment. quantify synthetic instrumental satellite geomagnetic generation. dipole averaged dipole moment dipole deviations oceania dipole moment europe asia. weighting option mitigate dipole moment approach. directional palaeomagnetic spite inhomogeneity presents reliable geomagnetic dipole moment | non_dup | [] |
25061934 | 10.1007/s00024-014-0921-9 | Hydraulic fracturing (fracking) using high pressures and a low viscosity
fluid allow the extraction of large quantiles of oil and gas from very low
permeability shale formations. The initial production of oil and gas at depth
leads to high pressures and an extensive distribution of natural fractures
which reduce the pressures. With time these fractures heal, sealing the
remaining oil and gas in place. High volume fracking opens the healed fractures
allowing the oil and gas to flow the horizontal productions wells. We model the
injection process using invasion percolation. We utilize a 2D square lattice of
bonds to model the sealed natural fractures. The bonds are assigned random
strengths and the fluid, injected at a point, opens the weakest bond adjacent
to the growing cluster of opened bonds. Our model exhibits burst dynamics in
which the clusters extends rapidly into regions with weak bonds. We associate
these bursts with the microseismic activity generated by fracking injections. A
principal object of this paper is to study the role of anisotropic stress
distributions. Bonds in the $y$-direction are assigned higher random strengths
than bonds in the $x$-direction. We illustrate the spatial distribution of
clusters and the spatial distribution of bursts (small earthquakes) for several
degrees of anisotropy. The results are compared with observed distributions of
microseismicity in a fracking injection. Both our bursts and the observed
microseismicity satisfy Gutenberg-Richter frequency-size statistics.Comment: 14 pages, 10 figure | Anisotropy in Fracking: A Percolation Model for Observed Microseismicity | anisotropy in fracking: a percolation model for observed microseismicity | hydraulic fracturing fracking pressures viscosity extraction quantiles permeability shale formations. pressures extensive fractures pressures. fractures heal sealing place. fracking opens healed fractures allowing productions wells. injection invasion percolation. utilize bonds sealed fractures. bonds assigned strengths injected opens weakest bond adjacent growing opened bonds. exhibits burst extends rapidly bonds. associate bursts microseismic fracking injections. principal anisotropic distributions. bonds assigned strengths bonds direction. illustrate bursts earthquakes anisotropy. microseismicity fracking injection. bursts microseismicity satisfy gutenberg richter pages | non_dup | [] |
33450540 | 10.1007/s00024-014-0927-3 | We combine geological data and ground motion estimates from satellite ERS-1/2 and ENVISAT persistent scatterer interferometry (PSI) to delineate areas of observed natural and anthropogenic geohazards in the administrative area of Greater London (United Kingdom). This analysis was performed within the framework of the EC FP7-SPACE PanGeo project, and by conforming to the interpretation and geohazard mapping methodology extensively described in the Production Manual (cf. http://www.pangeoproject.eu). We discuss the results of the generation of the PanGeo digital geohazard mapping product for Greater London, and analyse the potential of PSI, geological data and the PanGeo methodology to identify areas of observed geohazards. Based on the analysis of PSI ground motion data sets for the years 1992–2000 and 2002–2010 and geology field campaigns, we identify 25 geohazard polygons, covering a total of ~650 km2. These include not only natural processes such as compaction of deposits on the River Thames flood plain and slope instability, but also anthropogenic instability due to groundwater management and changes in the Chalk aquifer, recent engineering works such as those for the Jubilee Line Extension project and electricity tunnelling in proximity to the River Thames, and the presence of made ground. In many instances, natural and anthropogenic observed geohazards overlap, therefore indicating interaction of different processes over the same areas. In terms of ground area covered, the dominant geohazard is anthropogenic land subsidence caused by groundwater abstraction for a total of ~300 km2, followed by natural compression of River Thames sediments over ~105 km2. Observed ground motions along the satellite line-of-sight are as high as +29.5 and −25.3 mm/year, and indicate a combination of land surface processes comprising ground subsidence and uplift, as well as downslope movements. Across the areas of observed geohazards, urban land cover types from the Copernicus (formerly GMES) EEA European Urban Atlas, e.g., continuous and discontinuous urban fabric and industrial units, show the highest average velocities away from the satellite sensor, and the smallest standard deviations (~0.7–1.0 mm/year). More rural land cover types such as agricultural, semi-natural and green areas reveal the highest spatial variability (up to ~4.4 mm/year), thus suggesting greater heterogeneity of observed motion rates within these land cover types. Areas of observed motion in the PSI data for which a geological interpretation cannot be found with sufficient degree of certainty are also identified, and their possible causes discussed. Although present in Greater London, some geohazard types such as shrink–swell clays and ground dissolution are not highlighted by the interpretation of PSI annual motion rates. Reasons for absence of evidence of the latter in the PSI data are discussed, together with difficulties related to the identification of good radar scatterers in landsliding areas | Natural and anthropogenic geohazards in Greater London observed from geological and ERS-1/2 and ENVISAT Persistent Scatterers ground motion data: results from the EC FP7-SPACE PanGeo Project | natural and anthropogenic geohazards in greater london observed from geological and ers-1/2 and envisat persistent scatterers ground motion data: results from the ec fp7-space pangeo project | combine geological satellite envisat persistent scatterer interferometry delineate anthropogenic geohazards administrative kingdom pangeo conforming geohazard methodology extensively manual www.pangeoproject.eu pangeo digital geohazard analyse geological pangeo methodology geohazards. geology campaigns geohazard polygons covering compaction deposits river thames flood plain instability anthropogenic instability groundwater chalk aquifer jubilee electricity tunnelling proximity river thames ground. instances anthropogenic geohazards overlap areas. covered geohazard anthropogenic subsidence groundwater abstraction compression river thames sediments motions satellite sight comprising subsidence uplift downslope movements. geohazards cover copernicus formerly gmes atlas e.g. discontinuous fabric industrial velocities away satellite sensor smallest deviations rural cover agricultural reveal heterogeneity cover types. geological certainty discussed. geohazard shrink–swell clays dissolution highlighted rates. reasons difficulties radar scatterers landsliding | non_dup | [] |
25007512 | 10.1007/s00024-014-0962-0 | U.S. Tsunami Warning Centers use real-time bottom pressure (BP) data
transmitted from a network of buoys deployed in the Pacific and Atlantic Oceans
to tune source coefficients of tsunami forecast models. For accurate
coefficients and therefore forecasts, tides at the buoys must be accounted for.
In this study, five methods for coefficient estimation are compared, each of
which accounts for tides differently. The first three subtract off a tidal
prediction based on (1) a localized harmonic analysis involving 29 days of data
immediately preceding the tsunami event, (2) 68 pre-existing harmonic
constituents specific to each buoy, and (3) an empirical orthogonal function
fit to the previous 25 hrs of data. Method (4) is a Kalman smoother that uses
method (1) as its input. These four methods estimate source coefficients after
detiding. Method (5) estimates the coefficients simultaneously with a
two-component harmonic model that accounts for the tides. The five methods are
evaluated using archived data from eleven DART buoys, to which selected
artificial tsunami signals are superimposed. These buoys represent a full range
of observed tidal conditions and background BP noise in the Pacific and
Atlantic, and the artificial signals have a variety of patterns and induce
varying signal-to-noise ratios. The root-mean-square errors (RMSEs) of least
squares estimates of sources coefficients using varying amounts of data are
used to compare the five detiding methods. The RMSE varies over two orders of
magnitude between detiding methods, generally decreasing in the order listed,
with method (5) yielding the most accurate estimate of source coefficient. The
RMSE is substantially reduced by waiting for the first full wave of the tsunami
signal to arrive. As a case study, the five method are compared using data
recorded from the devastating 2011 Japan tsunami.Comment: 20 pages; 3 tables; 15 figure | Detiding DART buoy data for real-time extraction of source coefficients
for operational tsunami forecasting | detiding dart buoy data for real-time extraction of source coefficients for operational tsunami forecasting | u.s. tsunami warning centers transmitted buoys deployed pacific atlantic oceans tune tsunami forecast models. forecasts tides buoys accounted for. accounts tides differently. subtract tidal localized harmonic involving immediately preceding tsunami harmonic constituents buoy orthogonal data. kalman smoother input. detiding. simultaneously harmonic accounts tides. archived eleven dart buoys artificial tsunami superimposed. buoys tidal pacific atlantic artificial induce ratios. rmses squares amounts detiding methods. rmse varies orders detiding decreasing listed yielding coefficient. rmse substantially waiting tsunami arrive. devastating pages tables | non_dup | [] |
76968991 | 10.1007/s00024-014-0986-5 | The aim of this study is to better understand how a layered basalt sequence affects the propagation of a seismic wave, which has implications for sub-basalt seismic imaging. This is achieved by the construction of detailed, realistic models of basalt sequences, using data derived directly from outcrop analogues. Field data on the surface roughness of basaltic lava flows were captured using terrestrial laser scanning and satellite remote sensing. The fractal properties of the surface roughness were derived, and it can be shown that the lava flow surface is fractal over length scales up to approximately 2 km. The fractal properties were then used to construct synthetic lava flow surfaces using a von Karman power spectrum, and the resulting surfaces were then stacked to create a synthetic lava flow sequence. P-wave velocity data were then added, and the resulting model was used to generate synthetic seismic data. The resulting stacked section shows that the ability to resolve the internal structure of the lava flows is quickly lost due to scattering and attenuation by the basalt pile. A further result from generating wide-angle data is that the appearance of a lower-velocity layer below the basalt sequence may be caused by destructive interference within the basalt itself | On the use of fractal surfaces to understand seismic wave propagation in layered basalt sequences. | on the use of fractal surfaces to understand seismic wave propagation in layered basalt sequences. | layered basalt affects propagation seismic basalt seismic imaging. realistic basalt outcrop analogues. roughness basaltic lava flows captured terrestrial scanning satellite remote sensing. fractal roughness lava fractal fractal synthetic lava karman stacked create synthetic lava sequence. synthetic seismic data. stacked resolve lava flows quickly lost attenuation basalt pile. generating appearance basalt destructive interference basalt | non_dup | [] |
33107823 | 10.1007/s00024-014-1009-2 | The south of the Iberian Peninsula is a region situated at the convergence of the Eurasian and African plates. This region experiences large earthquakes with a long separation in time, the best known of which is the great 1755 Lisbon Earthquake (i.e., maximum macroseismic intensity, Imax=X), which occurred SW of San Vicente Cape (SW Iberian Peninsula). The high risk of damaging earthquakes has recently lead Carranza et al. (2013) to investigate the feasibility of an EEWS in this region. The analysis of the geometrical situation between the Iberian seismic networks and the San Vicente Cape area led the authors to conclude that a threshold-based approach, which would not require the real-time location of the earthquake, might be the best option for EEWS in SW Iberia. The current work explores this hypothesis, and proposes a new EEW approach that extends the standard P-wave threshold based single station analysis to the whole network. The proposed method allows the real-time estimation of the potential damage at stations that are triggered by P-waves, as well as at the not-triggered ones, giving the advantage of a greater lead-time for the release of alerts. Results of tests made with synthetic data mimicking the scenario of the great 1755 Lisbon Earthquake, and those obtained by applying the new approach to available recordings, indicate that an EEW estimation of the potential damage associated with an event in the San Vicente Cape area can be obtained for a very large portion of the Iberian Peninsula | A Threshold-Based Earthquake Early-Warning System for Offshore Events in Southern Iberia | a threshold-based earthquake early-warning system for offshore events in southern iberia | iberian peninsula situated eurasian african plates. experiences earthquakes great lisbon earthquake i.e. macroseismic imax occurred vicente cape iberian peninsula damaging earthquakes carranza feasibility eews region. geometrical iberian seismic vicente cape earthquake option eews iberia. explores proposes extends station network. stations triggered triggered giving advantage alerts. synthetic mimicking great lisbon earthquake recordings vicente cape portion iberian peninsula | non_dup | [] |
41153562 | 10.1007/s00024-014-1022-5 | In order to better characterize P-wave velocities for the shallow crust of the Po Plain
and surrounding regions, we have selected 64 deep wells mainly located in the plain
and also along the Apennine belt and Adriatic coast. In particular, we have analyzed
the stratigraphic profiles for all wells, and the available sonic logs (37 out of 64).
From these data we have examinated the P-wave velocity trend with depth and
estimated rock density following an empirical relationship between sonic velocity and
density in sedimentary rocks. Then we have calculated, notably for the first time in a
large area of Italy, the overburden stress magnitude for each well. For instance at a
depth of 5 km we have found values varying from 105 to 130 MPa moving from the
Adriatic coast to the Apennine belt. Consequently, the Apennines belt shows a
maximum regional lithostatic gradient of around 26 MPa/km while the Po Plain and
Adriatic region have values of around 21 MPa/km. The maximum density value that
can be considered for the Apennine crustal belt corresponds to 2.65 g/cm3; in the Po
Plain the mean density is around 2.25 g/cm3, while in the Adriatic area the average
density has the lowest value in the region at 2.13 g/cm3. Although in this area a 2D
crustal P-wave velocity model does not adequately constrain the complicated and
uneven tectonics, we have nevertheless established a shallow model consisting of five
separate layers. The strength of this paper lies in the possible use of these direct data,
together with other derived geological and geophysical information, to build a 3D
model of the area | P-wave velocity, density and vertical stress magnitude along the crustal Po Plain (northern Italy) from sonic log drilling data | p-wave velocity, density and vertical stress magnitude along the crustal po plain (northern italy) from sonic log drilling data | characterize velocities shallow crust plain surrounding wells plain apennine belt adriatic coast. stratigraphic wells sonic logs examinated rock sonic sedimentary rocks. notably overburden well. moving adriatic coast apennine belt. apennines belt lithostatic plain adriatic apennine crustal belt plain adriatic crustal adequately constrain complicated uneven tectonics nevertheless shallow consisting layers. lies geological geophysical build | non_dup | [] |
70661339 | 10.1007/s00024-015-1060-7 | Throughout history, the Lower Tagus Valley (LTV) region has been shaken by several earthquakes, including some with moderate to large magnitudes and with sources located inside the basin, for example the 1344 (M6.0) and 1909 (M6.0) earthquakes. Previous simulations (Bezzeghoud et al. Natural Hazard 69:
1229–1245, 2011) have revealed strong amplification of the amplitude waves in the region, because of the effect of the low-velocity sediments that fill the basin. The model used in those simulations was updated in this work by including new high-resolution geophysical and geotechnical data available for the area (seismic reflection, aeromagnetic, gravimetric, deep wells, standard penetration tests, and geological data). To contribute to improved assessment of seismic hazard in the LTV, we simulated propagation of seismic waves produced by moderate earthquakes in a 3D heterogeneous medium by using elastic finite-difference wave propagation code. The method, successfully used by Grandin et al. (Geophys J Int 171: 1144–1161, 2007), involves evaluation of the seismic potential of known faults in the area studied and three-dimensional seismic ground motion modelling by use of finite difference methods. On the basis of this methodology, we calculated the ground motion for the April 23, 1909, Benavente (Portugal) earthquake (Mw = 6.0) in dense grid points, then computed the synthetic isoseismic map of the area by use of appropriate relationships between seismic intensity (MMI) and peak ground velocity (PGV). The synthetic results, in contrast with available macroseismic and instrumental data, enable validation of the source models proposed for the area, identification of the
sources of historical earthquakes, and could also indicate which areas are more exposed to seismic ground motion | Ground-motion simulation in the Lower Tagus Valley Basin | ground-motion simulation in the lower tagus valley basin | tagus valley shaken earthquakes moderate magnitudes basin earthquakes. bezzeghoud hazard amplification sediments fill basin. updated geophysical geotechnical seismic reflection aeromagnetic gravimetric wells penetration geological seismic hazard propagation seismic moderate earthquakes heterogeneous elastic propagation code. successfully grandin geophys involves seismic faults seismic methods. methodology april benavente portugal earthquake dense synthetic isoseismic seismic synthetic macroseismic instrumental enable validation historical earthquakes exposed seismic | non_dup | [] |
81224308 | 10.1007/s00024-015-1063-4 | The article of record as published may be found at http://dx.doi.org/10.1007/s00024-015-1063-4Classical Ekman spiral is generated by surface wind stress with constant eddy viscosity in
homogeneous ocean. In real oceans, the eddy viscosity varies due to turbulent mixing caused by
surface wind and buoyancy forcing. Horizontally inhomogeneous density produces vertical geostrophic
shear which contributes to current shear that also affects the Ekman spiral. Based on the similar
theoretical framework as the classical Ekman spiral, the baroclinic components of the Ekman spiral
caused by the horizontally inhomogeneous density are obtained analytically with the varying eddy
viscosity calculated from surface wind and buoyancy forcing using the K- Profile Parameterization
(KPP). Along with the three existing types of eddy viscosity due to pure wind forcing (zero surface
buoyancy flux), such an effect is evaluated using the climatological monthly mean data of surface
wind stress, buoyancy flux, ocean temperature and salinity, and mixed layer depth | Ekman spiral in horizontally inhomogeneous ocean with varying eddy viscosity | ekman spiral in horizontally inhomogeneous ocean with varying eddy viscosity | record ekman spiral eddy viscosity homogeneous ocean. oceans eddy viscosity varies turbulent buoyancy forcing. horizontally inhomogeneous produces geostrophic contributes affects ekman spiral. ekman spiral baroclinic ekman spiral horizontally inhomogeneous analytically eddy viscosity buoyancy forcing parameterization eddy viscosity forcing buoyancy climatological monthly buoyancy ocean salinity | non_dup | [] |
33452361 | 10.1007/s00024-015-1071-4 | Recent advances in multi-temporal Differential Synthetic Aperture Radar (SAR) Interferometry (DInSAR) have greatly improved our capability to monitor geological processes. Ground motion studies using DInSAR require both the availability of good quality input data and rigorous approaches to exploit the retrieved Time Series (TS) at their full potential. In this work we present a methodology for DInSAR TS analysis, with particular focus on landslides and subsidence phenomena. The proposed methodology consists of three main steps: (1) pre-processing, i.e., assessment of a SAR Dataset Quality Index (SDQI) (2) post-processing, i.e., application of empirical/stochastic methods to improve the TS quality, and (3) trend analysis, i.e., comparative implementation of methodologies for automatic TS analysis. Tests were carried out on TS datasets retrieved from processing of SAR imagery acquired by different radar sensors (i.e., ERS-1/2 SAR, RADARSAT-1, ENVISAT ASAR, ALOS PALSAR, TerraSAR-X, COSMO-SkyMed) using advanced DInSAR techniques (i.e., SqueeSAR™, PSInSAR™, SPN and SBAS). The obtained values of SDQI are discussed against the technical parameters of each data stack (e.g., radar band, number of SAR scenes, temporal coverage, revisiting time), the retrieved coverage of the DInSAR results, and the constraints related to the characterization of the investigated geological processes. Empirical and stochastic approaches were used to demonstrate how the quality of the TS can be improved after the SAR processing, and examples are discussed to mitigate phase unwrapping errors, and remove regional trends, noise and anomalies. Performance assessment of recently developed methods of trend analysis (i.e., PS-Time, Deviation Index and velocity TS) was conducted on two selected study areas in Northern Italy affected by land subsidence and landslides. Results show that the automatic detection of motion trends enhances the interpretation of DInSAR data, since it provides an objective picture of the deformation behaviour recorded through TS and therefore contributes to the understanding of the on-going geological processes | A user-oriented methodology for DInSAR time series analysis and interpretation: landslides and subsidence case studies | a user-oriented methodology for dinsar time series analysis and interpretation: landslides and subsidence case studies | advances synthetic aperture radar interferometry dinsar greatly capability monitor geological processes. dinsar availability rigorous exploit retrieved potential. methodology dinsar landslides subsidence phenomena. methodology i.e. dataset sdqi i.e. stochastic i.e. comparative methodologies automatic analysis. datasets retrieved imagery acquired radar sensors i.e. radarsat envisat asar alos palsar terrasar cosmo skymed advanced dinsar i.e. squeesar™ psinsar™ sbas sdqi stack e.g. radar scenes coverage revisiting retrieved coverage dinsar geological processes. stochastic mitigate unwrapping remove anomalies. i.e. northern subsidence landslides. automatic enhances dinsar picture deformation contributes going geological | non_dup | [] |
96770782 | 10.1007/s00024-015-1102-1 | This document is the Accepted Manuscript version of the following article: Tiwari, P.R., Kar, S.C., Mohanty, U.C. et al. Pure Appl. Geophys. (2016) 173: 657. https://doi.org/10.1007/s00024-015-1102-1. The final publication is available at Springer via: http://dx.doi.org/10.1007/s00024-015-1102-1. ?? Springer Basel 2015.In the present study, simulations have been carried out to study the relationship between winter-time precipitations and the large-scale global forcing (ENSO) using the tropical band version of Regional Climate Model (RegT-Band) for 5 El Nin??o and 4 La Nin??a years. The RegT-Band model is integrated with the observed sea-surface temperature and lateral boundary conditions from National Center for Environmental Prediction (NCEP)- Department of Energy (DOE) reanalysis 2 (NCEP-DOE2). The model domain extends from 50S to 50N and covers the entire tropics at a grid spacing of 45 km, i.e., it includes lateral boundary forcing only at the southern and northern boundaries. The performance evaluation of the model in capturing the large-scale fields followed by ENSO response with winter-time precipitation has been carried out by using model simulations against NCEP-DOE2 and Global Precipitation Climatology Project (GPCP) precipitation data. The analysis suggests that the model is able to reproduce the upper airfields and large-scale precipitation during winter time, although the model has some systematic biases compared to the observations. A comparison of model-simulated precipitation with observed precipitation at 17 station locations has been carried out. It is noticed that the RegT-Band model simulations are able to bring out the observed features reasonably well. Therefore, this preliminary study indicates that the tropical band version of the regional climate model can be effectively used for the better understanding of the large-scale global forcing | Simulations of Tropical Circulation and Winter Precipitation Over North India: an Application of a Tropical Band Version of Regional Climate Model (RegT-Band) | simulations of tropical circulation and winter precipitation over north india: an application of a tropical band version of regional climate model (regt-band) | document tiwari p.r. s.c. mohanty u.c. appl. geophys. publication springer springer basel winter precipitations forcing enso tropical regt years. regt lateral ncep reanalysis ncep extends covers tropics spacing i.e. lateral forcing southern northern boundaries. capturing enso winter precipitation ncep precipitation climatology gpcp precipitation data. reproduce airfields precipitation winter biases observations. precipitation precipitation station locations out. noticed regt bring reasonably well. preliminary tropical effectively forcing | non_dup | [] |
84676213 | 10.1007/s00024-015-1192-9 | We model the spatial and temporal evolution of October 8, 2005 Kashmir earthquake’s aftershock activity using the rate-and-state dependent friction model incorporating uncertainties in computed coseismic stress perturbations. We estimated the best possible value for frictional resistance ‘‘Arn’’, background seismicity rate ‘‘r’’ and coefficient of stress variation ‘‘CV’’ using maximum log-likelihood method. For the whole Kashmir earthquake sequence, we measure a frictional resistance Arn * 0.0185 MPa, r * 20 M3.7? events/year and CV = 0.94 ± 0.01. The spatial and temporal forecasted seismicity rate of modeled aftershocks fits well with the spatial and temporal distribution of observed aftershocks that occurred in the regions with positive static stress changes as well as in the apparent stress shadow region. To quantify the effect of secondary aftershock triggering, we have re-run the estimations for 100 stochastically declustered catalogs showing that the effect of aftershock-induced secondary stress changes is obviously minor compared to the overall uncertainties, and that the stress variability related to uncertain slip model inversions and receiver mechanisms remains the major factor to provide a reasonable data fit | Modeling of Kashmir Aftershock Decay Based on Static Coulomb Stress Changes and Laboratory-Derived Rate-and-State Dependent Friction Law | modeling of kashmir aftershock decay based on static coulomb stress changes and laboratory-derived rate-and-state dependent friction law | october kashmir earthquake’s aftershock friction incorporating coseismic perturbations. frictional ‘‘arn’’ seismicity ‘‘r’’ coefficient ‘‘cv’’ likelihood method. kashmir earthquake frictional forecasted seismicity modeled aftershocks aftershocks occurred apparent shadow region. quantify aftershock triggering estimations stochastically declustered catalogs aftershock obviously minor uncertain slip inversions receiver reasonable | non_dup | [] |
83842282 | 10.1007/s00024-015-1229-0 | An extensive data set of water level measurements of the September 2015
Chilean tsunami in rivers in Japan and a new methodology for data processing
are used to verify that tsunami dissipation in a river at each instant and
locality depends on the tidally-modified wave-locked slope of the river
surface. As deduced from the observations, a relatively small tsunami or ocean
noise traveling at mild wave-locked slopes can propagate virtually without
losses to the upstream locations where observed tidal ranges are a fraction of
that downstream; though at the higher slopes, tidal and riverine currents
combined efficiently damp the shorter waves. The observed correlations between
the tsunami admittance upriver and the traveled wave-locked slopes are
explained analytically under the fully-nonlinear shallow-water approximation.
It is found that the wave-locked slope in a purely incident wave relates to the
bottom drag in the same manner as a steady surface slope does for a stationary
flow. For a small-amplitude tsunami in the study rivers, the wave-locked slope
in a co-propagating tidal wave defines the background current and thereby
friction experienced by the tsunami.Comment: 25 pages, 12 figure | Tsunami penetration in tidal rivers, with observations of the Chile 2015
tsunami in rivers in Japan | tsunami penetration in tidal rivers, with observations of the chile 2015 tsunami in rivers in japan | extensive september chilean tsunami rivers methodology verify tsunami dissipation river instant locality tidally locked river surface. deduced tsunami ocean traveling mild locked slopes propagate virtually losses upstream locations tidal ranges downstream slopes tidal riverine currents efficiently damp shorter waves. tsunami admittance upriver traveled locked slopes analytically shallow approximation. locked purely incident relates drag manner steady stationary flow. tsunami rivers locked propagating tidal defines thereby friction experienced pages | non_dup | [] |
76971177 | 10.1007/s00024-016-1267-2 | We have implemented the WRF-Chem model version 3.5 over Poland to quantify the direct and indirect feedback effects of aerosols on simulated meteorology and aerosol concentrations. Observations were compared with results from three simulations at high spatial resolutions of 5 × 5 km: (1) BASE—without any aerosol feedback effects; (2) DIR—with direct aerosol-radiative effects (3) INDIR—with direct and indirect aerosol-radiative effects. We study the overall effect during January 2011 as well as selected episodes of the highest differences in PM10 concentrations between the three simulations. For the DIR simulation, the decrease in monthly mean incoming solar radiation (SWDOWN) appears for the entire study area. It changes geographically, from about −8.0 to −2.0 W m−2, respectively for the southern and northern parts of the country. The highest changes do not correspond to the highest PM10 concentration. Due to the solar radiation changes, the surface mean monthly temperature (T2) decreases for 96 % of the area of Poland, but not more than 1.0 °C. Monthly mean PBLH changes by more than ±5 m for 53 % of the domain. Locally the differences in PBLH between the DIR and BASE are higher than ± 20 m. Due to the direct effect, for 84 % of the domain, the mean monthly PM10 concentrations increase by up to 1.9 µg m−3. For the INDIR simulation the spatial distribution of changes in incoming solar radiation as well as air temperature is similar to the DIR simulation. The decrease of SWDOWN is noticed for the entire domain and for 23 % of the domain is higher than −5.0 W m−2. The absolute differences of PBLH are slightly higher for INDIR than DIR but similarly distributed spatially. For daily episodes, the differences between the simulations are higher, both for meteorology and PM10 concentrations, and the pattern of changes is usually more complex. The results indicate the potential importance of the aerosol feedback effects on modelled meteorology and PM10 concentrations | Aerosol-radiation feedback and PM10 air concentrations over Poland | aerosol-radiation feedback and pm10 air concentrations over poland | implemented poland quantify indirect aerosols meteorology aerosol concentrations. resolutions base—without aerosol dir—with aerosol radiative indir—with indirect aerosol radiative effects. episodes simulations. monthly incoming swdown area. geographically southern northern country. concentration. monthly poland monthly pblh domain. locally pblh monthly indir incoming simulation. swdown noticed pblh indir spatially. episodes meteorology complex. aerosol modelled meteorology | non_dup | [] |
76971178 | 10.1007/s00024-016-1272-5 | In this work, we present the results of high-resolution dynamical downscaling of air temperature, relative humidity, wind speed and direction, for the area of Poland, with the Weather Research and Forecasting (WRF) model. The model is configured using three nested domains, with spatial resolution of 45 km × 45 km, 15 km × 15 km and 5 km × 5 km. The ERA-Interim database is used for boundary conditions. The results are evaluated by comparison with station measurements for the period 1981–2010. The model is capable of reproducing the main climatological features of the study area. The results are in very close agreement with the measurements, especially for the air temperature. For all four meteorological variables, the model performance captures seasonal and daily cycles. For the air temperature and winter season, the model underestimates the measurements. For summer, the model shows higher values, compared with the measurements. The opposite is the case for relative humidity. There is a strong diurnal pattern in mean error, which changes seasonally. The agreement with the measurements is worse for the seashore and mountain areas, which suggests that the 5 km × 5 km grid might still have an insufficient spatial resolution. There is no statistically significant temporal trend in the model performance. The larger year-to-year changes in the model performance, e.g. for the years 1982 and 2010 for the air temperature should therefore be linked with the natural variability of meteorological conditions | High-resolution dynamical downscaling of ERA-Interim using the WRF regional climate model for the area of Poland. Part 1: Model configuration and statistical evaluation for the 1981–2010 period | high-resolution dynamical downscaling of era-interim using the wrf regional climate model for the area of poland. part 1: model configuration and statistical evaluation for the 1981–2010 period | downscaling humidity poland weather forecasting model. configured nested interim conditions. station capable reproducing climatological area. temperature. meteorological captures seasonal cycles. winter season underestimates measurements. summer measurements. opposite humidity. diurnal seasonally. worse seashore mountain insufficient resolution. statistically performance. e.g. meteorological | non_dup | [] |
76971179 | 10.1007/s00024-016-1273-4 | This paper presents the application of the high-resolution WRF model data for the automatic classification of the atmospheric circulation types and the evaluation of the model results for daily rainfall and air temperatures. The WRF model evaluation is performed by comparison with measurements and gridded data (E-OBS). The study is focused on the area of Poland and covers the 1981–2010 period, for which the WRF model has been run using three nested domains with spatial resolution of 45 km × 45 km, 15 km × 15 km and 5 km × 5 km. For the model evaluation, we have used the data from the innermost domain, and data from the second domain were used for circulation typology. According to the circulation type analysis, the anticyclonic types (AAD and AAW) are the most frequent. The WRF model is able to reproduce the daily air temperatures and the error statistics are better, compared with the interpolation-based gridded dataset. The high-resolution WRF model shows a higher spatial variability of both air temperature and rainfall, compared with the E-OBS dataset. For the rainfall, the WRF model, in general, overestimates the measured values. The model performance shows a seasonal pattern and is also dependent on the atmospheric circulation type, especially for daily rainfall | High-resolution dynamical downscaling of ERA-Interim using the WRF regional climate model for the area of Poland. Part 2: Model performance with respect to automatically derived circulation types | high-resolution dynamical downscaling of era-interim using the wrf regional climate model for the area of poland. part 2: model performance with respect to automatically derived circulation types | presents automatic circulation rainfall temperatures. gridded focused poland covers nested innermost circulation typology. circulation anticyclonic frequent. reproduce interpolation gridded dataset. rainfall dataset. rainfall overestimates values. seasonal circulation rainfall | non_dup | [] |
45451272 | 10.1007/s00024-016-1331-y | Bartolomé, Rafael ... et. al.-- Special issue Geodynamics of the Latin American Pacific Margin.-- 20 pages, 11 figuresDuring the TSUJAL marine geophysical survey, conducted in February and March 2014, Spanish, Mexican and British scientists and technicians explored the western margin of Mexico, considered one of the most active seismic zones in America. This work aims to characterize the internal structure of the subduction zone of the Rivera plate beneath the North American plate in the offshore part of the Jalisco Block, to link the geodynamic and the recent tectonic deformation occurring there with the possible generation of tsunamis and earthquakes. For this purpose, it has been carried out acquisition, processing and geological interpretation of a multichannel seismic reflection profile running perpendicular to the margin. Crustal images show an oceanic domain, dominated by subduction–accretion along the lower slope of the margin with a subparallel sediment thickness of up to 1.6 s two-way travel time (approx. 2 km) in the Middle American Trench. Further, from these data the region appears to be prone to giant earthquake production. The top of the oceanic crust (intraplate reflector) is very well imaged. It is almost continuous along the profile with a gentle dip (<10°); however, it is disrupted by normal faulting resulting from the bending of the plate during subduction. The continental crust presents a well-developed accretionary prism consisting of highly deformed sediments with prominent slumping towards the trench that may be the result of past tsunamis. Also, a bottom simulating reflector (BSR) is identified in the first half a second (twtt) of the section. High amplitude reflections at around 7–8 s twtt clearly image a discontinuous Moho, defining a very gentle dipping subduction planeWe gratefully acknowledge financial support from MINECO (Spain) through TSUJAL project (CGL2011-29474-C02-01) and “Ramon y Cajal” program (R. Bartolome), and from Mexico through CONACYT–FOMIXJAL 2008–96567 (2009); CONACYT–FOMIXJAL 2008–96539 (2009); CONACYT–FOMIXJAL 2010–149245 (2011); CONACyT-FOMIXJal (2012-08-189963) and also partial funding was provided by UNAM DGAPA Grant #IN115513-3Peer Reviewe | Multichannel Seismic Imaging of the Rivera Plate Subduction at the Seismogenic Jalisco Block Area (Western Mexican Margin) | multichannel seismic imaging of the rivera plate subduction at the seismogenic jalisco block area (western mexican margin) | bartolomé rafael geodynamics latin pacific margin. pages figuresduring tsujal marine geophysical february spanish mexican british scientists technicians explored margin mexico seismic zones america. aims characterize subduction rivera plate beneath plate offshore jalisco geodynamic tectonic deformation occurring tsunamis earthquakes. acquisition geological multichannel seismic reflection running perpendicular margin. crustal oceanic dominated subduction–accretion margin subparallel sediment travel approx. trench. prone giant earthquake production. oceanic crust intraplate reflector imaged. gentle disrupted faulting bending plate subduction. continental crust presents accretionary prism consisting deformed sediments prominent slumping trench tsunamis. simulating reflector twtt section. reflections twtt discontinuous moho defining gentle dipping subduction planewe gratefully acknowledge mineco spain tsujal “ramon cajal” bartolome mexico conacyt–fomixjal conacyt–fomixjal conacyt–fomixjal conacyt fomixjal funding unam dgapa peer reviewe | non_dup | [] |
146476417 | 10.1007/s00024-016-1351-7 | The 2011 Tohoku tsunami entered the Kitakami river and propagated there as a
train of shock waves, recorded with a 1-min interval at water level stations at
Fukuchi, Iino, and the weir 17.2 km from the mouth, where the bulk of the wave
was reflected back. The records showed that each bore kept its shape and
identity as it traveled a 10.9-km-path Fukuchi-Iino-weir-Iino. Shock handling
based on the cross-river integrated classical shock conditions was applied to
reconstruct the flow velocity time histories at the measurement sites, to
estimate inflow into the river at each site, to evaluate the wave heights of
incident and reflected tsunami bores near the weir, and to estimate propagation
speed of the individual bores. Theoretical predictions are verified against the
measurements. We discuss experiences of exercising the shock conditions with
actual tsunami measurements in the Kitakami river, and test applicability of
the shallow-water approximation for describing tsunami bores with heights
ranging from 0.3 m to 4 m in a river segment with a depth of 3-4 m.Comment: 26 pages, 13 figure | Tsunami Bores in Kitakami River | tsunami bores in kitakami river | tohoku tsunami entered kitakami river propagated train shock stations fukuchi iino weir mouth reflected back. records bore kept traveled fukuchi iino weir iino. shock handling river shock reconstruct histories inflow river heights incident reflected tsunami bores weir propagation bores. verified measurements. experiences exercising shock tsunami kitakami river applicability shallow describing tsunami bores heights ranging river segment pages | non_dup | [] |
42725744 | 10.1007/s00024-016-1412-y | One difficulty in developing numerical methods for tsunami modeling is the
fact that solutions contain regions where much higher resolution is required
than elsewhere in the domain, particularly since the solution may contain
discontinuities or other localized features. The Clawpack software deals with
this issue by using block-structured adaptive mesh refinement to selectively
refine around propagating waves. For problems where only a target area of the
total solution is of interest (e.g. one coastal community), a method that
allows identifying and refining the grid only in regions that influence this
target area would significantly reduce the computational cost of finding a
solution.
In this work, we show that solving the time-dependent adjoint equation and
using a suitable inner product with the forward solution allows more precise
refinement of the relevant waves. We present examples solving the shallow water
equations in one and two dimensions. To perform these simulations, the use of
the adjoint method has been integrated into the adaptive mesh refinement
strategy of the open source GeoClaw software. We also present results that show
that the accuracy of the solution is maintained and the computational time
required is significantly reduced through the integration of the adjoint method
into adaptive mesh refinement.Comment: Much of this material appeared in a previous pre-print, which can be
found at arXiv:1511.03645 . Here, the material has been rewritten to focus on
shallow water equations and submitted to a more application focused journa | Adjoint Methods for Guiding Adaptive Mesh Refinement in Tsunami Modeling | adjoint methods for guiding adaptive mesh refinement in tsunami modeling | difficulty tsunami elsewhere discontinuities localized features. clawpack deals structured adaptive mesh refinement selectively refine propagating waves. e.g. coastal identifying refining solution. solving adjoint precise refinement waves. solving shallow dimensions. adjoint adaptive mesh refinement geoclaw software. maintained adjoint adaptive mesh appeared print rewritten shallow submitted focused journa | non_dup | [] |
42725898 | 10.1007/s00024-017-1545-7 | Air radon concentration measurement is useful for research on geophysical
effects, but it is strongly sensitive to site geology and many geophysical and
microclimatic processes such as wind, ventilation, air humidity and so on that
induce very big fluctuations on the concentration of radon in air. On the
contrary, monitoring the radon concentration in soil by measuring the thermal
neutron flux reduces environmental effects. In this paper we report some
experimental results on the natural thermal neutron flux as well as the
concentration of air radon and its variations at 4300 m a.s.l. These results
were obtained with unshielded thermal neutron scintillation detectors
(en-detectors) and radon monitors located inside the ARGO-YBJ experimental
hall. The correlation of these variations with the lunar month and 1-year
period is undoubtedly confirmed. A method for earthquakes prediction provided
by a global net of the en-detectors is currently under study.Comment: 16 pages, 7 figure | Seasonal and Lunar month periods observed in natural neutron flux at
high altitude | seasonal and lunar month periods observed in natural neutron flux at high altitude | radon geophysical geology geophysical microclimatic ventilation humidity induce radon air. contrary radon measuring neutron reduces effects. neutron radon a.s.l. unshielded neutron scintillation detectors detectors radon monitors argo hall. lunar month undoubtedly confirmed. earthquakes detectors pages | non_dup | [] |
195708871 | 10.1007/s00024-017-1735-3 | The viscoelastic deformation of an elastic–viscoelastic composite system is significantly different from that of a simple viscoelastic medium. Here, we show that complicated transient deformation due to viscoelastic stress relaxation after a megathrust earthquake can occur even in a very simple situation, in which an elastic surface layer (lithosphere) is underlain by a viscoelastic substratum (asthenosphere) under gravity. Although the overall decay rate of the system is controlled by the intrinsic relaxation time constant of the asthenosphere, the apparent decay time constant at each observation point is significantly different from place to place and generally much longer than the intrinsic relaxation time constant of the asthenosphere. It is also not rare that the sense of displacement rate is reversed during the viscoelastic relaxation. If we do not bear these points in mind, we may draw false conclusions from observed deformation data. Such complicated transient behavior can be explained mathematically from the characteristics of viscoelastic solution: for an elastic–viscoelastic layered half-space, the viscoelastic solution is expressed as superposition of three decaying components with different relaxation time constants that depend on wavelength | Characteristics of viscoelastic crustal deformation following a megathrust earthquake: discrepancy between the apparent and intrinsic relaxation time constants | characteristics of viscoelastic crustal deformation following a megathrust earthquake: discrepancy between the apparent and intrinsic relaxation time constants | viscoelastic deformation elastic–viscoelastic composite viscoelastic medium. complicated transient deformation viscoelastic relaxation megathrust earthquake elastic lithosphere underlain viscoelastic substratum asthenosphere gravity. intrinsic relaxation asthenosphere apparent intrinsic relaxation asthenosphere. rare displacement reversed viscoelastic relaxation. bear mind draw false deformation data. complicated transient mathematically viscoelastic elastic–viscoelastic layered viscoelastic superposition decaying relaxation | non_dup | [] |
83848521 | 10.1007/s00024-017-1745-1 | This paper examines the questions of whether smaller asteroids that burst in
the air over water can generate tsunamis that could pose a threat to distant
locations. Such air burst-generated tsunamis are qualitatively different than
the more frequently studied earthquake-generated tsunamis, and differ as well
from impact asteroids. Numerical simulations are presented using the shallow
water equations in several settings, demonstrating very little tsunami threat
from this scenario. A model problem with an explicit solution that demonstrates
and explains the same phenomena found in the computations is analyzed. We
discuss the question of whether compressibility and dispersion are important
effects that should be included, and show results from a more sophisticated
model problem using the linearized Euler equations that begins to addresses
this.Comment: submitte | Air-burst Generated Tsunamis | air-burst generated tsunamis | examines asteroids burst tsunamis pose threat distant locations. burst tsunamis qualitatively frequently earthquake tsunamis asteroids. shallow settings demonstrating tsunami threat scenario. demonstrates explains phenomena computations analyzed. compressibility sophisticated linearized euler begins addresses submitte | non_dup | [] |
146459857 | 10.1007/s00024-018-1774-4 | Natural fractures are ubiquitous in the Earth’s crust and often deeply buried in the subsurface. Due to the difficulty in accessing to their three-dimensional structures, the study of fracture network geometry is usually achieved by sampling two-dimensional (2D) exposures at the Earth’s surface through outcrop mapping or aerial photograph techniques. However, the measurement results can be considerably affected by the coverage of forests and other plant species over the exposed fracture patterns. We quantitatively study such effects using numerical simulation. We consider the scenario of nominally isotropic natural fracture systems and represent them using 2D discrete fracture network models governed by fractal and length scaling parameters. The groundcover is modelled as random patches superimposing onto the 2D fracture patterns. The effects of localisation and total coverage of landscape patches are further investigated. The fractal dimension and length exponent of the covered fracture networks are measured and compared with those of the original non-covered patterns. The results show that the measured length exponent increases with the reduced localisation and increased coverage of landscape patches, which is more evident for networks dominated by very large fractures (i.e. small underlying length exponent). However, the landscape coverage seems to have a minor impact on the fractal dimension measurement. The research findings of this paper have important implications for field survey and statistical analysis of geological systems | Influence of Landscape Coverage on Measuring Spatial and Length Properties of Rock Fracture Networks: Insights from Numerical Simulation | influence of landscape coverage on measuring spatial and length properties of rock fracture networks: insights from numerical simulation | fractures ubiquitous earth’s crust deeply buried subsurface. difficulty accessing fracture exposures earth’s outcrop aerial photograph techniques. considerably coverage forests exposed fracture patterns. quantitatively simulation. nominally isotropic fracture fracture governed fractal parameters. groundcover modelled patches superimposing fracture patterns. localisation coverage landscape patches investigated. fractal exponent covered fracture covered patterns. exponent localisation coverage landscape patches evident dominated fractures i.e. exponent landscape coverage minor fractal measurement. geological | non_dup | [] |
2590861 | 10.1007/s00025-003-0081-1 | We consider classes $ \mathcal{A}_M(S) $ of functions holomorphic in an open
plane sector $ S $ and belonging to a strongly non-quasianalytic class on the
closure of $ S $. In $ \mathcal{A}_M(S) $, we construct functions which are
flat at the vertex of $ S $ with a sharp rate of vanishing. This allows us to
obtain a Borel-Ritt type theorem for $ \mathcal{A}_M(S) $ extending previous
results by Schmets and Valdivia. We also derive a division property for ideals
of flat ultradifferentiable functions, in the spirit of a classical $ C^\infty
$ result of Tougeron.Comment: Slight update of the published version. The definition of closedness
in subsections 4.1 and 4.2 is less restrictive. One minor typo correcte | Division by Flat Ultradifferentiable Functions and Sectorial Extensions | division by flat ultradifferentiable functions and sectorial extensions | mathcal holomorphic belonging quasianalytic closure mathcal sharp vanishing. borel ritt mathcal extending schmets valdivia. derive division ideals ultradifferentiable spirit infty slight update version. closedness subsections restrictive. minor typo correcte | non_dup | [] |
2099051 | 10.1007/s00025-009-0014-8 | Let $X$ be a finitistic space having the mod 2 cohomology algebra of the
product of two projective spaces. We study free involutions on $X$ and
determine the possible mod 2 cohomology algebra of orbit space of any free
involution, using the Leray spectral sequence associated to the Borel fibration
$X \hookrightarrow X_{\mathbb{Z}_2} \longrightarrow B_{\mathbb{Z}_2}$. We also
give an application of our result to show that if $X$ has the mod 2 cohomology
algebra of the product of two real projective spaces (respectively complex
projective spaces), then there does not exist any $\mathbb{Z}_2$-equivariant
map from $\mathbb{S}^k \to X$ for $k \geq 2$ (respectively $k \geq 3$), where
$\mathbb{S}^k$ is equipped with the antipodal involution.Comment: 14 pages, to appear in Results in Mathematic | Orbit spaces of free involutions on the product of two projective spaces | orbit spaces of free involutions on the product of two projective spaces | finitistic cohomology projective spaces. involutions cohomology orbit involution leray borel fibration hookrightarrow mathbb longrightarrow mathbb cohomology projective projective mathbb equivariant mathbb mathbb equipped antipodal pages mathematic | non_dup | [] |
55708197 | 10.1007/s00025-009-0015-7 | By applying a reflection principle we set up fully explicit representation formulas for the harmonic Green's function for orthogonal sectors of the annulus of the unit ball of R-n. From the harmonic Green's function we then can determine the Bergman kernel function of Clifford holomorphic functions by applying an appropriate vector differentiation. As a concrete application we give an explicit analytic representation formula of the solutions to an n-dimensional Dirichlet problem in annular shaped domains that arises in the context of heat conduction | Explicit formulas for the Green's function and the Bergman kernel for monogenic functions in annular shaped domains in Rn+1 | explicit formulas for the green's function and the bergman kernel for monogenic functions in annular shaped domains in rn+1 | reflection formulas harmonic orthogonal sectors annulus ball harmonic bergman kernel clifford holomorphic differentiation. concrete analytic dirichlet annular shaped arises conduction | non_dup | [] |
24932208 | 10.1007/s00025-010-0081-x | In this paper we consider simply connected Lie groups equipped with left
invariant Randers metrics which arise from left invariant Riemannian metrics
and left invariant vector fields. Then we study the intersection between
automorphism and isometry groups of these spaces. Finally it has shown that for
any left invariant vector field, in a special case, the Lie group admits a left
invariant Randers metric such that this intersection is a maximal compact
subgroup of the group of automorphisms with respect to which the considered
vector field is invariant | The Relation Between Automorphism Group and Isometry Group of Randers
Lie Groups | the relation between automorphism group and isometry group of randers lie groups | equipped randers metrics arise riemannian metrics fields. intersection automorphism isometry spaces. admits randers intersection maximal subgroup automorphisms | non_dup | [] |
2153882 | 10.1007/s00025-012-0254-x | Let $L=\Delta-\nabla\varphi\cdot\nabla$ be a symmetric diffusion operator
with an invariant measure $d\mu=e^{-\varphi}dx$ on a complete Riemannian
manifold. In this paper we prove Li-Yau gradient estimates for weighted
elliptic equations on the complete manifold with $|\nabla \varphi|\leq\theta$
and $\infty$-dimensional Bakry-\'{E}mery Ricci curvature bounded below by some
negative constant. Based on this, we give an upper bound on the first
eigenvalue of the diffusion operator $L$ on this kind manifold, and thereby
generalize a Cheng's result on the Laplacian case (Math. Z., 143 (1975)
289-297).Comment: Final version. The original proof of Theorem 2.1 using Li-Yau
gradient estimate method has been moved to the appendix. The new proof is
simple and direc | Upper bounds on the first eigenvalue for a diffusion operator via
Bakry-\'{E}mery Ricci curvature II | upper bounds on the first eigenvalue for a diffusion operator via bakry-\'{e}mery ricci curvature ii | delta nabla varphi cdot nabla varphi riemannian manifold. weighted elliptic manifold nabla varphi theta infty bakry mery ricci curvature constant. eigenvalue kind manifold thereby generalize cheng laplacian math. .comment version. moved appendix. direc | non_dup | [] |
55734566 | 10.1007/s00025-013-0309-7 | Let ${\bf D}_{\bf x}:= \sum_{i=1}^n \frac{\partial }{\partial x_i} e_i$ be the Euclidean Dirac operator in $\R^n$ and let $P(X) = a_m X^m + \ldots + a_1 X + a_0$ be a polynomial with real coefficients. Differential equations of the form $P({\bf D}_{\bf x})u({\bf x}) = 0$ are called homogeneous polynomial Dirac equations with real coefficients. In this paper we treat Dirichlet type problems of the a slighly less general form $P({\bf D}_{\bf x}) u({\bf x}) = f({\bf x})$ (where the roots are exclusively real) with prescribed boundary conditions that avoid blow-ups inside of the domain. We set up analytic representation formulas for the solutions in terms of hypercomplex integral operators and give exact formulas for the integral kernels in the particular cases dealing with spherical and concentric annular domains. The Maxwell and the Klein Gordon equation are included as special subcases in this context | On dirichlet type problems of polynomial dirac equations with boundary conditions | on dirichlet type problems of polynomial dirac equations with boundary conditions | frac euclidean dirac ldots coefficients. homogeneous dirac coefficients. treat dirichlet slighly roots exclusively prescribed avoid blow domain. analytic formulas hypercomplex formulas kernels dealing spherical concentric annular domains. maxwell klein gordon subcases | non_dup | [] |
34635201 | 10.1007/s00025-015-0462-2 | We examine curvature properties of twisted surfaces with null rotation axis in Minkowski 3-space. That is, we study surfaces that arise when a planar curve is subject to two synchronized rotations, possibly at different speeds, one in its supporting plane and one of this supporting plane about an axis in the plane. Moreover, at least one of the two rotation axes is a null axis. As is clear from its construction, a twisted surface generalizes the concept of a surface of revolution. We classify flat, constant Gaussian curvature, minimal and constant mean curvature twisted surfaces with a null rotation axis. Aside from pseudospheres, pseudohyperbolic spaces and cones, we encounter B-scrolls in these classifications. The appearance of B-scrolls in these classifications is of course the result of the rotation about a null axis. As for the cones in the classification of flat twisted surfaces, introducing proper coordinates, we prove that they are determined by so-called Clelia curves. With a Clelia curve we mean a curve that has linear dependent spherical coordinates.status: publishe | Twisted Surfaces with Null Rotation Axis in Minkowski 3-Space | twisted surfaces with null rotation axis in minkowski 3-space | examine curvature twisted minkowski space. arise planar synchronized rotations possibly speeds supporting supporting plane. axes axis. twisted generalizes revolution. classify curvature curvature twisted axis. aside pseudospheres pseudohyperbolic cones encounter scrolls classifications. appearance scrolls classifications axis. cones twisted introducing proper clelia curves. clelia spherical coordinates.status publishe | non_dup | [] |
29513676 | 10.1007/s00025-015-0464-0 | The object of study are almost complex manifolds with a pair of Norden
metrics, mutually associated by means of the almost complex structure. More
precisely, a torsion-free connection and tensors with geometric interpretation
are found which are invariant under the twin interchange, i.e. the swap of the
counterparts of the pair of Norden metrics and the corresponding Levi-Civita
connections. A Lie group depending on four real parameters is considered as an
example of a 4-dimensional manifold of the studied type. The mentioned
invariant objects are found in an explicit form.Comment: 13 page | Invariant Tensors under the Twin Interchange of Norden Metrics on Almost
Complex Manifolds | invariant tensors under the twin interchange of norden metrics on almost complex manifolds | manifolds norden metrics mutually structure. precisely torsion connection tensors geometric twin interchange i.e. swap counterparts norden metrics levi civita connections. manifold type. | non_dup | [] |
25031343 | 10.1007/s00025-015-0467-x | We consider a boundary value problem in the half-space for a linear parabolic
equation of fourth order with a degeneration on the boundary of the half-space.
The equation under consideration is substantially a linearized thin film
equation. We prove that, if the right hand side of the equation and the
boundary condition are polynomials in the tangential variables and time, the
same property has any solution of a power growth. It is shown also that the
specified property does not apply to normal variable. As an application, we
present a theorem of uniqueness for the problem in the class of functions of
power growth.Comment: The final version is available on Springer at DOI:
10.1007/s00025-015-0467- | Liouville property for solutions of the linearized degenerate thin film
equation of fourth order in a halfspace | liouville property for solutions of the linearized degenerate thin film equation of fourth order in a halfspace | parabolic fourth degeneration space. consideration substantially linearized film equation. polynomials tangential growth. specified variable. uniqueness springer | non_dup | [] |
24953237 | 10.1007/s00025-015-0510-y | The lack of an inner product structure in Banach spaces yields the motivation
to introduce a semi-inner product with a more general axiom system, one missing
the requirement for symmetry, unlike the one determing a Hilbert space. We use
it on a finite dimensional real Banach space $(\X, \| \cdot\|)$ to define and
investigate three concepts. First, we generalize that of \emph{antinorms},
already defined in Minkowski planes, for even dimensional spaces. Second, we
introduce \emph{normality maps}, which in turn leads us to the study of
\emph{semi-polarity}, a variant of the notion of polarity, which makes use of
the underlying semi-inner product.Comment: 16 page | Semi-inner products and the concept of semi-polarity | semi-inner products and the concept of semi-polarity | banach motivation axiom missing requirement unlike determing hilbert space. banach cdot concepts. generalize emph antinorms minkowski planes spaces. emph normality emph polarity variant notion polarity | non_dup | [] |
42648086 | 10.1007/s00025-016-0616-x | Since the introduction of the concept of isotopism of algebras by Albert in
1942, a prolific literature on the subject has been developed for distinct
types of algebras. Nevertheless, there barely exists any result on the problem
of distributing Lie algebras into isotopism classes. The current paper is a
first step to deal with such a problem. Specifically, we define a new series of
isotopism invariants and we determine explicitly the distribution into
isotopism classes of $n$-dimensional filiform Lie algebras, for $n\leq 7$. We
also deal with the distribution of such algebras into isomorphism classes, for
which we confirm some known results and we prove that there exist $p+8$
isomorphism classes of seven-dimensional filiform Lie algebras over the finite
field $\mathbb{F}_p$ if $p\neq 2$.Comment: 20 pages, preliminary versio | Isomorphism and isotopism classes of filiform Lie algebras of dimension
up to seven | isomorphism and isotopism classes of filiform lie algebras of dimension up to seven | isotopism algebras albert prolific algebras. nevertheless barely distributing algebras isotopism classes. deal problem. isotopism invariants explicitly isotopism filiform algebras deal algebras isomorphism confirm isomorphism seven filiform algebras mathbb .comment pages preliminary versio | non_dup | [] |
87756509 | 10.1007/s00025-016-0619-7 | For singular plane curves, the classical definitions of envelopes are vague. In order to define envelopes for singular plane curves, we introduce a one-parameter family of Legendre curves in the unit tangent bundle over the Euclidean plane and the curvature. Then we give a definition of an envelope for the one-parameter family of Legendre curves. We investigate properties of the envelopes. For instance, the envelope is also a Legendre curve. Moreover, we consider bi-Legendre curves and give a relationship between envelopes | Envelopes of Legendre Curves in the Unit Tangent Bundle over the Euclidean Plane | envelopes of legendre curves in the unit tangent bundle over the euclidean plane | singular definitions envelopes vague. envelopes singular legendre tangent bundle euclidean curvature. envelope legendre curves. envelopes. envelope legendre curve. legendre envelopes | non_dup | [] |
42641833 | 10.1007/s00025-016-0624-x | An associated Nijenhuis tensor of endomorphisms in the tangent bundle is
introduced. Special attention is paid to such tensors for an almost
hypercomplex structure and the metric of Hermitian-Norden type. There are
studied relations between the six associated Nijenhuis tensors as well as their
vanishing. It is given a geometric interpretation of the vanishing of these
tensors as a necessary and sufficient condition for the existence of a unique
connection with totally skew-symmetric torsion tensor. Similar idea is used in
the paper of T. Friedrich and S. Ivanov in Asian J. Math. (2002) for some other
structures. Finally, an example of a 4-dimensional manifold of the considered
type with vanishing associated Nijenhuis tensors is given.Comment: 13 page | Associated Nijenhuis Tensors on Manifolds with Almost Hypercomplex
Structures and Metrics of Hermitian-Norden Type | associated nijenhuis tensors on manifolds with almost hypercomplex structures and metrics of hermitian-norden type | nijenhuis endomorphisms tangent bundle introduced. paid tensors hypercomplex hermitian norden type. nijenhuis tensors vanishing. geometric vanishing tensors connection totally skew torsion tensor. friedrich ivanov asian math. structures. manifold vanishing nijenhuis tensors | non_dup | [] |
42689404 | 10.1007/s00025-016-0645-5 | It is known that the structure of invariant subspaces of the Hardy space
$H^2(\mathbb D^n)$ on the polydisc $\mathbb{D}^n$ is very complicated; hence,
we need good examples help us to understand the structure of invariant
subspaces of $H^2(\mathbb D^n)$. In this paper, we define two types of
invariant subspaces of $H^2(\mathbb D^n)$. Then, we give a characterization of
these types invariant subspaces in view of the Beurling-Lax-Halmos Theorem.
Unitary equivalence is also studied in this paper.Comment: 8 pages, this is a preliminary version of the paper and all
comments/suggestions are welcom | Two types of invariant Subspaces in the polydisc | two types of invariant subspaces in the polydisc | subspaces hardy mathbb polydisc mathbb complicated subspaces mathbb subspaces mathbb subspaces beurling halmos theorem. unitary equivalence pages preliminary comments suggestions welcom | non_dup | [] |
73370083 | 10.1007/s00025-017-0686-4 | A representation for compact 3-manifolds with non-empty non-spherical
boundary via 4-colored graphs (i.e., 4-regular graphs endowed with a proper
edge-coloration with four colors) has been recently introduced by two of the
authors, and an initial classification of such manifolds has been obtained up
to 8 vertices of the representing graphs. Computer experiments show that the
number of graphs/manifolds grows very quickly as the number of vertices
increases. As a consequence, we have focused on the case of orientable
3-manifolds with toric boundary, which contains the important case of
complements of knots and links in the 3-sphere. In this paper we obtain the
complete catalogation/classification of these 3-manifolds up to 12 vertices of
the associated graphs, showing the diagrams of the involved knots and links.
For the particular case of complements of knots, the research has been extended
up to 16 vertices.Comment: 19 pages, 6 figures, 3 tables; changes in Lemma 6, Corollaries 7 and | 4-colored graphs and knot/link complements | 4-colored graphs and knot/link complements | manifolds empty spherical colored i.e. endowed proper coloration colors manifolds representing graphs. manifolds grows quickly increases. focused orientable manifolds toric complements knots links sphere. catalogation manifolds diagrams knots links. complements knots pages tables corollaries | non_dup | [] |
86414873 | 10.1007/s00025-017-0691-7 | We present a non-standard proof of the fact that the existence of a local
(i.e. restricted to a point) characteristic-zero, semi-parametric lifting for a
variety defined by the zero locus of polynomial equations over the integers is
equivalent to the existence of a collection of local semi-parametric
(positive-characteristic) reductions of such variety for almost all primes
(i.e. outside a finite set), and such that there exists a global complexity
bounding all the corresponding structures involved. Results of this kind are a
fundamental tool for transferring theorems in commutative algebra from a
characteristic-zero setting to a positive-characteristic one | On Positive-Characteristic Semi-Parametric Local-Uniform Reductions of
Varieties over Finitely Generated $\mathbb{Q}$-Algebras | on positive-characteristic semi-parametric local-uniform reductions of varieties over finitely generated $\mathbb{q}$-algebras | i.e. restricted parametric lifting locus integers parametric reductions primes i.e. bounding involved. kind transferring theorems commutative | non_dup | [] |
73346802 | 10.1007/s00025-017-0696-2 | Given a non-negative weight $v$, not necessarily bounded or strictly
positive, defined on a domain $G$ in the complex plane, we consider the
weighted space $H_v^\infty(G)$ of all holomorphic functions on $G$ such that
the product $v|f|$ is bounded in $G$ and study the question of when is such a
space complete under the canonical sup-seminorm. We obtain both some necessary
and some sufficient conditions in terms of the weight $v$, exhibit several
relevant examples, and characterize completeness in the case of spaces with
radial weights on balanced domains.Comment: 20 pages. The title of the first version was confusing and was
changed accordingly in the second version. In the third version several
misprints have been corrected and some explanations have been clarified and
in the fourth version a few minor misprints were correcte | A note on completeness of weighted normed spaces of analytic functions | a note on completeness of weighted normed spaces of analytic functions | necessarily strictly weighted infty holomorphic canonical seminorm. exhibit characterize completeness weights balanced pages. title confusing changed accordingly version. misprints corrected explanations clarified fourth minor misprints correcte | non_dup | [] |
141870339 | 10.1007/s00025-017-0732-2 | Fueter's theorem discloses a remarkable connection existing between holomorphic functions and monogenic functions when m is odd. It states that is monogenic if is holomorphic and is a homogeneous monogenic polynomial in . Eelbode et al. (AIP Conf Proc 1479:340-343, 2012) proved that this statement is still valid if the monogenicity condition on is dropped. To obtain this result, the authors used representation theory methods but their result also follows from a direct calculus we established in our paper Pea Pea and Sommen (J Math Anal Appl 365:29-35, 2010). In this paper we generalize the result from Eelbode et al. (2012) to the case of monogenic functions in biaxially symmetric domains. In order to achieve this goal we first generalize Pea Pea and Sommen (2010) to the biaxial case and then derive the main result from that | Fueter’s theorem for monogenic functions in biaxial symmetric domains | fueter’s theorem for monogenic functions in biaxial symmetric domains | fueter discloses remarkable connection holomorphic monogenic odd. monogenic holomorphic homogeneous monogenic eelbode conf proved statement valid monogenicity dropped. calculus sommen math anal appl generalize eelbode monogenic biaxially domains. goal generalize sommen biaxial derive | non_dup | [] |
187767925 | 10.1007/s00025-018-0833-6 | Functional equations satisfied by additive functions have a special interest not only in the theory of functional equations, but also in the theory of (commutative) algebra because the fundamental notions such as derivations and automorphisms are additive functions satisfying some further functional equations as well. It is an important question that how these morphisms can be characterized among additive mappings in general.\ud
The paper contains some multivariate characterizations of higher order derivations. The univariate characterizations are given as consequences by the diagonalization of the multivariate formulas. The method allows us to refine the process of computing the solutions of univariate functional equations of the form\ud
∑k=1nxpkfk(xqk)=0,\ud
where pk and qk (k=1,…,n) are given nonnegative integers and the unknown functions f1,…,fn:R→R are supposed to be additive on the ring R. It is illustrated by some explicit examples too.\ud
As another application of the multivariate setting we use spectral analysis and spectral synthesis in the space of the additive solutions to prove that such a functional equation characterizes derivations of higher order. The results are uniformly based on the investigation of the multivariate version of the functional equations | On functional equations characterizing derivations: methods and examples | on functional equations characterizing derivations: methods and examples | satisfied additive commutative notions derivations automorphisms additive satisfying well. morphisms additive mappings general. multivariate characterizations derivations. univariate characterizations consequences diagonalization multivariate formulas. refine univariate nxpkfk nonnegative integers unknown supposed additive illustrated too. multivariate additive characterizes derivations order. uniformly multivariate | non_dup | [] |
129353814 | 10.1007/s00025-018-0843-4 | Gavruta introduced $K$-frames for Hilbert spaces to study atomic systems with
respect to a bounded linear operator. There are many differences between
K-frames and standard frames, so we study weaving properties of K-frames. Two
frames $\{\phi_{i}\}_{i \in I}$ and $\{\psi_{i}\}_{i \in I}$ for a separable
Hilbert space $\mathcal{H}$ are woven if there are positive constants $A \leq
B$ such that for every subset $\sigma \subset I$, the family $\{\phi_{i}\}_{i
\in \sigma} \cup \{\psi_{i}\}_{i \in \sigma^{c}}$ is a frame for $\mathcal{H}$
with frame bounds $A, B$. In this paper, we present necessary and sufficient
conditions for weaving $K$-frames in Hilbert spaces. It is shown that woven
$K$-frames and weakly woven $K$-frames are equivalent. Finally, sufficient
conditions for Paley-Wiener type perturbation of weaving $K$-frames are given | Weaving K-frames in Hilbert Spaces | weaving k-frames in hilbert spaces | gavruta frames hilbert operator. frames frames weaving frames. frames separable hilbert mathcal woven sigma sigma sigma mathcal bounds weaving frames hilbert spaces. woven frames weakly woven frames equivalent. paley wiener perturbation weaving frames | non_dup | [] |
84094558 | 10.1007/s00025-018-0845-2 | Two triangle meshes are conformally equivalent if for any pair of incident
triangles the absolute values of the corresponding cross-ratios of the four
vertices agree. Such a pair can be considered as preimage and image of a
discrete conformal map. In this article we study discrete conformal maps which
are defined on parts of a triangular lattice $T$ with strictly acute angles.
That is, $T$ is an infinite triangulation of the plane with congruent strictly
acute triangles. A smooth conformal map $f$ can be approximated on a compact
subset by such discrete conformal maps $f^\varepsilon$, defined on a part of
$\varepsilon T$ for $\varepsilon>0$ small enough, see [U. B\"ucking,
Approximation of conformal mappings using conformally equivalent triangular
lattices, in "Advances in Discrete Differential Geometry" (A.I. Bobenko ed.),
Springer (2016), 133--149]. We improve this result and show that the
convergence is in fact in $C^\infty$. Furthermore, we describe how the
cross-ratios of the four vertices for pairs of incident triangles are related
to the Schwarzian derivative of $f$.Comment: 17 pages, 3 figure | $C^\infty$-convergence of conformal mappings on triangular lattices | $c^\infty$-convergence of conformal mappings on triangular lattices | triangle meshes conformally incident triangles agree. preimage conformal map. conformal triangular strictly angles. infinite triangulation congruent strictly triangles. conformal approximated conformal varepsilon varepsilon varepsilon ucking conformal mappings conformally triangular lattices advances a.i. bobenko springer infty incident triangles schwarzian .comment pages | non_dup | [] |
66655 | 10.1007/s00026-004-0229-z | The graph-theoretic operation of rooted subtree prune and regraft is increasingly being used as a tool for understanding and modelling reticulation events in evolutionary biology. In this paper, we show that computing the rooted subtree prune and regraft distance between two rooted binary phylogenetic trees on the same label set is NP-hard. This resolves a longstanding open problem. Furthermore, we show that this distance is xed parameter tractable when parameterised by the distance between the two trees | On the computational complexity of the rooted subtree prune and regraft distance. | on the computational complexity of the rooted subtree prune and regraft distance. | theoretic rooted subtree prune regraft increasingly reticulation evolutionary biology. rooted subtree prune regraft rooted phylogenetic trees label hard. resolves longstanding problem. tractable parameterised trees | non_dup | [] |
2658390 | 10.1007/s00026-006-0289-3 | We study entanglement properties of mixed density matrices obtained from
combinatorial Laplacians. This is done by introducing the notion of the density
matrix of a graph. We characterize the graphs with pure density matrices and
show that the density matrix of a graph can be always written as a uniform
mixture of pure density matrices of graphs. We consider the von Neumann entropy
of these matrices and we characterize the graphs for which the minimum and
maximum values are attained. We then discuss the problem of separability by
pointing out that separability of density matrices of graphs does not always
depend on the labelling of the vertices. We consider graphs with a tensor
product structure and simple cases for which combinatorial properties are
linked to the entanglement of the state. We calculate the concurrence of all
graph on four vertices representing entangled states. It turns out that for
some of these graphs the value of the concurrence is exactly fractional.Comment: 20 pages, 11 figure | The laplacian of a graph as a density matrix: a basic combinatorial
approach to separability of mixed states | the laplacian of a graph as a density matrix: a basic combinatorial approach to separability of mixed states | entanglement combinatorial laplacians. introducing notion graph. characterize mixture graphs. neumann characterize attained. separability pointing separability labelling vertices. combinatorial entanglement state. concurrence representing entangled states. turns concurrence pages | non_dup | [] |