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We present two uniqueness results for the inverse problem of determining an index of refraction by the corresponding acoustic far-field measurement encoded into the scattering amplitude. The first one is a local uniqueness in determining a…

Analysis of PDEs · Mathematics 2013-08-28 Guanghui Hu , Hongyu Liu

A Green's function in an acoustic medium can be retrieved from reflection data by solving a multidimensional Marchenko equation. This procedure requires a-priori knowledge of the initial focusing function, which can be interpreted as the…

Applied Physics · Physics 2025-08-11 Joost van der Neut , Joeri Brackenhoff , Giovanni Meles , Lele Zhang , Evert Slob , Kees Wapenaar

This paper studies the reconstruction of Stekloff eigenvalues and the index of refraction of an inhomogeneous medium from Cauchy data. The inverse spectrum problem to reconstruct Stekloff eigenvalues is investigated using a new integral…

Mathematical Physics · Physics 2019-09-04 Juan Liu , Yanfang Liu , Jiguang Sun

A classical problem in acoustic (and electromagnetic) scattering concerns the evaluation of the Green's function for the Helmholtz equation subject to impedance boundary conditions on a half-space. The two principal approaches used for…

Numerical Analysis · Mathematics 2012-11-28 Michael O'Neil , Leslie Greengard , Andras Pataki

A variety of problems in acoustic and electromagnetic scattering require the evaluation of impedance or layered media Green's functions. Given a point source located in an unbounded half-space or an infinitely extended layer, Sommerfeld and…

Numerical Analysis · Mathematics 2015-07-23 Jun Lai , Leslie Greengard , Michael O'Neil

This paper presents a new methodology for the solution of problems of two- and three-dimensional acoustic scattering (and, in particular, two-dimensional electromagnetic scattering) by obstacles and defects in presence an arbitrary number…

Numerical Analysis · Mathematics 2017-08-23 Oscar P. Bruno , Carlos Pérez-Arancibia

Acoustic imaging methods often ignore multiple scattering. This leads to false images in cases where multiple scattering is strong.Marchenko imaging has recently been introduced as a data-driven way to deal with internal multiple…

Applied Physics · Physics 2020-06-09 Kees Wapenaar , Christian Reinicke

We are concerned with the inverse scattering problem of recovering an inhomogeneous medium by the associated acoustic wave measurement. We prove that under certain assumptions, a single far-field pattern determines the values of a…

Analysis of PDEs · Mathematics 2020-05-05 Emilia Blåsten , Hongyu Liu

We deal with the scattering of an acoustic medium modeled by an index of refraction $n$ varying in a bounded region $\Omega$ of $\mathbb{R}^3$ and equal to unity outside $\Omega$. This region is perforated with an extremely large number of…

Analysis of PDEs · Mathematics 2016-10-20 Ahmed Alsaedi , Bashir Ahmed , Durga Prasad Challa , Mokhtar Kirane , Mourad Sini

We propose a reconstruction method to extract the variable mass density from the elastic farfields, with a single incident direction, measured before and after injecting highly dense small scaled inclusions. We take as a model, the Lam\'e…

Analysis of PDEs · Mathematics 2024-09-24 Durga Prasad Challa , Divya Gangadaraiah , Mourad Sini

Let $M$ be the number of bounded and Lipschitz regular obstacles $D_j, j:=1, ..., M$ having a maximum radius $a$, $a<<1$, located in a bounded domain $\Omega$ of $\mathbb{R}^3$. We are concerned with the acoustic scattering problem with a…

Analysis of PDEs · Mathematics 2016-10-20 Bashir Ahmad , Durga Prasad Challa , Mokhtar Kirane , Mourad Sini

In this paper, a new inversion model for 2D microwave imaging is introduced by means of a convenient rewriting of the usual Lippmann Schwinger integral scattering equation. Such model is derived by decomposing the Greens function and the…

Signal Processing · Electrical Eng. & Systems 2021-03-01 Martina T. Bevacqua , Tommaso Isernia

The present study deals with total internal reflection of a plane electromagnetic wave at an infinite plane boundary between a transparent medium and an amplifying or attenuating lower-index medium. Solutions of Maxwell's equations are…

Optics · Physics 2023-06-13 Takeyuki Kobayashi

This paper presents a second-kind surface integral equation method for the numerical solution of frequency-domain electromagnetic scattering problems by locally perturbed layered media in three spatial dimensions. Unlike standard…

Numerical Analysis · Mathematics 2022-11-10 Rodrigo Arrieta , Carlos Pérez-Arancibia

We are concerned with the inverse scattering problem of extracting the geometric structures of an unknown/inaccessible inhomogeneous medium by using the corresponding acoustic far-field measurement. Using the intrinsic geometric properties…

Analysis of PDEs · Mathematics 2017-06-15 Jingzhi Li , Xiaofei Li , Hongyu Liu

We formally deduce closed-form expressions for the transmitted effective wavenumber of a material comprising multiple types of inclusions or particles (multi-species), dispersed in a uniform background medium. The expressions, derived here…

Classical Physics · Physics 2018-05-09 Artur L. Gower , Michael J. A. Smith , William J. Parnell , Ian David Abrahams

Multiple scattering methods are widely used to reduce the computational complexity of acoustic or electromagnetic scattering problems when waves propagate through media containing many identical inclusions. Historically, this numerical…

Numerical Analysis · Mathematics 2024-08-07 Carlos Borges , Leslie Greengard , Michael O'Neil , Manas Rachh

This paper introduces a new Windowed Green Function (WGF) method for the numerical integral-equation solution of problems of electromagnetic scattering by obstacles in presence of dielectric or conducting half-planes. The WGF method, which…

Computational Physics · Physics 2015-08-05 Oscar Bruno , Mark Lyon , Carlos Perez-Arancibia , Catalin Turc

A domain integral method employing a specific Green's function (i.e., incorporating some features of the global problem of wave propagation in an inhomogeneous medium) is developed for solving direct and inverse scattering problems relative…

In this paper, we establish new results for the uniform far-field asymptotics of the two-layered Green function (together with its derivatives) in 2D in the frequency domain. To the best of our knowledge, our results are the sharpest yet…

Analysis of PDEs · Mathematics 2023-12-27 Long Li , Jiansheng Yang , Bo Zhang , Haiwen Zhang
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