Results 21 to 30 of about 2,942 (77)
On Convergence of Extended Dynamic Mode Decomposition to the Koopman Operator
, 2017 Extended Dynamic Mode Decomposition (EDMD) is an algorithm that approximates the action of the Koopman operator on an $N$-dimensional subspace of the space of observables by sampling at $M$ points in the state space.
Korda, Milan, Mezić, Igor
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Second kind functionals for the Laguerre-Hahn affine class on the unit circle [PDF]
, 2003 16 pages, no figures.-- MSC1991 codes: 33C47, 42C05.MR#: MR2032331 (2004j:33013)Zbl#: Zbl 1036.42024The aim of this paper is the study of some transformations in the Laguerre-Hahn affine class that do not preserve the class. Under very general conditions,
Cachafeiro, Alicia +2 more
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Entanglement properties of bound and resonant few-body states
, 2018 Studying the physics of quantum correlations has gained new interest after it has become possible to measure entanglement entropies of few body systems in experiments with ultracold atomic gases. Apart from investigating trapped atom systems, research on
Amico +49 more
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Dynamical stability criterion for inhomogeneous quasi-stationary states in long-range systems
, 2010 We derive a necessary and sufficient condition of linear dynamical stability for inhomogeneous Vlasov stationary states of the Hamiltonian Mean Field (HMF) model.
Alessandro Campa +20 more
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Mathematical Methods in the Applied Sciences, Volume 48, Issue 2, Page 2267-2293, 30 January 2025.We study the Helmholtz equation with periodic coefficients in a closed waveguide. A functional analytic approach is used to formulate and solve the radiation problem in a self‐contained exposition. In this context, we simplify the non‐degeneracy assumption on the frequency.
A. Kirsch, B. Schweizer
wiley +1 more source
Representations of hermitian kernels by means of Krein spaces II. Invariant kernels
, 2000 In this paper we study hermitian kernels invariant under the action of a semigroup with involution. We characterize those hermitian kernels which realize the given action by bounded operators on a Krein space.
Constantinescu, Tiberiu +1 more
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Journal of the London Mathematical Society, Volume 110, Issue 5, November 2024.Abstract The aim of this paper is to prove the existence of Hadamard states for the Maxwell equations on any globally hyperbolic spacetime. This will be achieved by introducing a new gauge fixing condition, the Cauchy radiation gauge, that will allow to suppress all the unphysical degrees of freedom. The key ingredient for achieving this gauge is a new
Simone Murro, Gabriel Schmid
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, 2017 We investigate linearized gauge theories on globally hyperbolic spacetimes in the BRST formalism. A consistent definition of the classical phase space and of its Cauchy surface analogue is proposed.
Wrochna, Michał, Zahn, Jochen
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Accelerating Nonequilibrium Green Functions Simulations: The G1–G2 Scheme and Beyond
physica status solidi (b), Volume 261, Issue 9, September 2024.This article reviews recent developments in the theory of nonequilibrium Green functions (NEGF) where dramatic accelerations are achieved within the time‐local G1–G2 scheme. As a result, longer simulations with more accurate selfenergies are possible. The figure shows an illustration ‐ optical excitation of graphene by a short laser pulse: snapshot of ...
Michael Bonitz +5 more
wiley +1 more source
Low dimensional manifolds for exact representation of open quantum systems
, 2017 Weakly nonlinear degrees of freedom in dissipative quantum systems tend to localize near manifolds of quasi-classical states. We present a family of analytical and computational methods for deriving optimal unitary model transformations based on ...
Amini, Nina Hadis +2 more
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