English
Related papers

Related papers: Multi-center Vector Field Methods for Wave Equatio…

200 papers

A major challenge of many diffraction calculations, using some form of the Rayleigh-Sommerfeld formulas, is the integration of a highly oscillatory integrand. Here we derive a potentially useful alternative form of solution to the Helmholtz…

Optics · Physics 2013-02-04 Daniel J. Merthe

Both null and timelike rays experience trajectory bending in a gravitational field. In this work, we systematically develop a perturbative method to compute the deflection angle of rays with general velocity $v$ in arbitrary static and…

General Relativity and Quantum Cosmology · Physics 2020-04-22 Junji Jia

We use the perturbation method to approximately solve subdiffusion-reaction equations. Within this method we obtain the solutions of the zeroth and the first order. The comparison our analytical solutions with the numerical results shown…

Statistical Mechanics · Physics 2012-01-18 Katarzyna D. Lewandowska , Tadeusz Kosztołowicz , Mateusz Piwnik

Long simulation times in climate sciences typically require coarse grids due to computational constraints. Nonetheless, unresolved subscale information significantly influences the prognostic variables and can not be neglected for reliable…

Numerical Analysis · Mathematics 2018-02-22 Konrad Simon , Jörn Behrens

The surface current method known in the theory of electromagnetic waves diffraction is generalized to be applied for the problems of diffraction radiation generated by a charged particle moving nearby an ideally-conducting screen in vacuum.…

Accelerator Physics · Physics 2009-11-05 D. V. Karlovets , A. P. Potylitsyn

In this paper, we consider the 1D wave equation where the spatial domain is a bounded interval. Assuming the initial conditions to be known, we are here interested in identifying an unknown source term, while we take the Neumann derivative…

Optimization and Control · Mathematics 2011-06-30 Marianne Chapouly , Mazyar Mirrahimi

Wave propagation phenomena in soils can be experimentally simulated using centrifuge scale models. An original excitation device (drop-ball arrangement) is proposed to generate short wave trains. Wave reflections on model boundaries are…

Classical Physics · Physics 2009-01-26 J. F. Semblat , M. P. Luong

The Mean Field Variational Bayes (MFVB) method is one of the most computationally efficient techniques for Bayesian inference. However, its use has been restricted to models with conjugate priors or those that require analytical…

Computation · Statistics 2023-05-18 Minh-Ngoc Tran , Paco Tseng , Robert Kohn

In our previous article [4] an approach to derive Papapetrou equations for constrained electromagnetic field was demonstrated by use of field variational principles. The aim of current work is to present more universal technique of…

General Relativity and Quantum Cosmology · Physics 2007-06-29 A. T. Muminov

A simple analytic method of estimating the error involved in using an approximate boundary condition for diffuse radiation in two adjoining scattering media with differing refractive index is presented. The method is based on asymptotic…

Optics · Physics 2015-05-28 Adrian C. Selden

Seismic data are commonly modeled by a high-frequency single scattering approximation. This amounts to a linearization in the medium coefficient about a smooth background. The discontinuities are contained in the medium perturbation. The…

Analysis of PDEs · Mathematics 2009-09-25 Christiaan C. Stolk , Maarten V. de Hoop

This paper presents a comprehensive review of the wave-function approach for derivation of the number-resolved Master equations, used for description of transport and measurement in mesoscopic systems. The review contains important…

Mesoscale and Nanoscale Physics · Physics 2017-06-20 Shmuel Gurvitz

A method is proposed for the analysis of the propagation of electromagnetic waves through a homogeneous slab of a medium with Drude-Lorentz dispersion behavior, and excited by a causal sinusoidal source. An expression of the time dependent…

Optics · Physics 2016-10-13 Mohamed Ismail , Boris Gralak

This paper is presented to give numerical solutions of some cases of nonlinear wave-like equations with variable coefficients by using Reduced Differential Transform Method (RDTM). RDTM can be applied most of the physical, engineering,…

Numerical Analysis · Mathematics 2014-07-21 Murat Gubes , Yildiray Keskin , Galip Oturanc

Astrometric observations can, in principle, be used to detect gravitational waves. In this paper we give a practical overview of the gravitational wave effects which can be expected specifically in small-field astrometric data. Particular…

General Relativity and Quantum Cosmology · Physics 2026-01-12 Robin Geyer , Sven Zschocke , Michael Soffel , Sergei Klioner , Lennart Lindegren , Uwe Lammers

An approach to diffraction tomography is investigated for two-dimensional image reconstruction of objects surrounded by an arbitrarily-shaped curve of sources and receivers. Based on the integral theorem of Helmholtz and Kirchhoff, the…

Mathematical Physics · Physics 2014-11-20 G. T. Clement

Many machine learning problems can be seen as approximating a \textit{target} distribution using a \textit{particle} distribution by minimizing their statistical discrepancy. Wasserstein Gradient Flow can move particles along a path that…

Machine Learning · Statistics 2024-06-07 Song Liu , Jiahao Yu , Jack Simons , Mingxuan Yi , Mark Beaumont

We consider radial solutions to the Cauchy problem for the linear wave equation with a small short-range electromagnetic potential (the "square version" of the massless Dirac equation with a potential) and zero initial data. We prove two a…

Analysis of PDEs · Mathematics 2007-05-23 Davide Catania

We develop a new dispersion minimizing compact finite difference scheme for the Helmholtz equation in 2 and 3 dimensions. The scheme is based on a newly developed ray theory for difference equations. A discrete Helmholtz operator and a…

Numerical Analysis · Mathematics 2016-04-13 Christiaan C. Stolk

An algorithm to estimate motion from satellite imagery is presented. Dense displacement fields are computed from time-separated images of of significant convective activity using a Bayesian formulation of the motion estimation problem.…

Atmospheric and Oceanic Physics · Physics 2007-05-23 Sai Ravela , Virat Chatdarong