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Related papers: Wigner-Smith Time Delay Matrix for Acoustic Scatte…

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A material that exhibits Willis coupling has constitutive equations that couple the pressure-strain and momentum-velocity relationships. This coupling arises from subwavelength asymmetry and non-locality in heterogeneous media. This paper…

Computational Physics · Physics 2019-03-06 Michael B. Muhlestein , Benjamin M. Goldsberry , Andrew N. Norris , Michael R. Haberman

This investigation is concerned with the 2D acoustic scattering problem of a plane wave propagating in a non-lossy fluid host and soliciting a linear, isotropic, macroscopically-homogeneous, lossy, flat-plane layer in which the mass density…

Applied Physics · Physics 2019-05-01 Armand Wirgin

We give a principled approach for the selection of a boundary integral, retarded potential representation for the solution of scattering problems for the wave equation in an exterior domain.

Numerical Analysis · Mathematics 2015-04-17 Charles L. Epstein , Leslie Greengard , Thomas Hagstrom

We present a Weakly Compressible SPH (WCSPH) formulation with a temporally variable speed of sound. The benefits of a time-varying sound speed formulation and the weaknesses of a constant sound speed formulation are worked out. It is shown…

Computational Physics · Physics 2023-10-09 Fabian Thiery , Nikolaus A. Adams , Stefan Adami

We study the Wigner-Smith time-delay matrix $Q$ of a ballistic quantum dot supporting $N$ scattering channels. We compute the $v$-point correlators of the power traces $\mathrm{Tr} Q^{\kappa}$ for arbitrary $v\geq1$ at leading order for…

Mathematical Physics · Physics 2016-04-12 Fabio Deelan Cunden , Francesco Mezzadri , Nick Simm , Pierpaolo Vivo

This paper is concerned with the problem of scattering of time-harmonic acoustic waves from an impenetrable obstacle in a piecewise homogeneous medium. The well-posedness of the direct problem is established, employing the integral equation…

Analysis of PDEs · Mathematics 2009-12-09 xiaodong Liu , Bo Zhang

The scattering phase, defined as $ \log \det S ( \lambda ) / 2\pi i $ where $ S ( \lambda ) $ is the (unitary) scattering matrix, is the analogue of the counting function for eigenvalues when dealing with exterior domains and is closely…

Spectral Theory · Mathematics 2022-10-19 Jeffrey Galkowski , Pierre Marchand , Jian Wang , Maciej Zworski

In this work we study the scattering and transfer matrices for electric fields defined with respect to an angular spectrum of plane waves. For these matrices, we derive the constraints that are enforced by conservation of energy,…

Optics · Physics 2021-02-17 Niall Byrnes , Matthew R. Foreman

This paper presents a numerical compression strategy for the boundary integral equation of acoustic scattering in two dimensions. These equations have oscillatory kernels that we represent in a basis of wave atoms, and compress by…

Numerical Analysis · Mathematics 2008-05-28 Laurent Demanet , Lexing Ying

We review recent progress in analysing wave scattering in systems with both intrinsic chaos and/or disorder and internal losses, when the scattering matrix is no longer unitary. By mapping the problem onto a nonlinear supersymmetric…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Y. V. Fyodorov , D. V. Savin , H. -J. Sommers

In this paper, a new representation of the Wigner function for a quantum system in the phase space is proposed. The new representation is of the form $W=\operatorname{Sp}\left[ \rho \mathcal{W} \right]$, where $\rho$ is the density matrix,…

Mathematical Physics · Physics 2019-04-11 E. E. Perepelkin , B. I. Sadovnikov , N. G. Inozemtseva , E. V. Burlakov

Motivated by recent interest in the zeroes of S-matrix entries in the complex energy plane, I use the Heidelberg model of resonance scattering to introduce the notion of Reflection Time Difference which is shown to play the same role for…

Disordered Systems and Neural Networks · Physics 2020-01-03 Yan V Fyodorov

In time series classification and regression, signals are typically mapped into some intermediate representation used for constructing models. Since the underlying task is often insensitive to time shifts, these representations are required…

Sound · Computer Science 2019-07-16 Joakim Andén , Vincent Lostanlen , Stéphane Mallat

Acoustic wave propagation in a fluid with a random assortment of identical cylindrical scatterers is considered. While the leading order correction to the effective wavenumber of the coherent wave is well established at dilute areal density…

Materials Science · Physics 2011-02-07 Andrew N. Norris , Jean-Marc Conoir

This paper investigates the problem of time-harmonic acoustic scattering in an inhomogeneous medium with a complex topological structure. Specifically, the medium is anisotropic and contains several disjoint sound-soft obstacles. This model…

Mathematical Physics · Physics 2025-09-30 Huaian Diao , Qingle Meng , Zhiying Sun

We describe a method of white-beam inelastic neutron scattering for improved measurement efficiency. The method consists of matrix inversion and selective extraction. The former is to resolve each incident energy component from the…

Materials Science · Physics 2015-03-19 K. Tomiyasu , M. Matsuura , H. Kimura , K. Iwasa , K. Ohoyama , T. Yokoo , S. Itoh , E. Kudoh , T. Sato , M. Fujita

We introduce a new numerical method for solving time-harmonic acoustic scattering problems. The main focus is on plane waves scattered by smoothly varying material inhomogeneities. The proposed method works for any frequency $\omega$, but…

Numerical Analysis · Mathematics 2022-01-14 Anton Arnold , Sjoerd Geevers , Ilaria Perugia , Dmitry Ponomarev

CConsider a bipartite quantum system consisting of two subsystems A and B. The reduced density matrix ofA a is obtained by taking the partial trace with respect to B. In this work, we will show that the Wigner distribution of this reduced…

Quantum Physics · Physics 2022-11-17 Maurice de Gosson , Charlyne de Gosson

Phase-space representations based on coherent states (P, Q, Wigner) have been successful in the creation of stochastic differential equations (SDEs) for the efficient stochastic simulation of high dimensional quantum systems. However many…

Quantum Physics · Physics 2015-05-14 M. R. Hush , A. R. R. Carvalho , J. J. Hope

The globalised cascaded scattering matrix technique is a well proven, practical method that can be used to simulate large accelerating RF structures in which realistic fabrication errors to be incorporated in an efficient manner without the…

Accelerator Physics · Physics 2014-11-18 I. Shinton , R. M. Jones