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We explore the effect of sampling rates when measuring data given by $Mf$ for special operators $M$ arising in Thermoacoustic Tomography. We start with sampling requirements on $Mf$ given $f$ satisfying certain conditions. After this we…

Analysis of PDEs · Mathematics 2019-12-11 Chase Mathison

The spectrum of the interior transmission problem is related to the unique determination of the acoustic properties of a body in thermoacoustic imaging. Under a non-trapping hypothesis, we show that sparsity of the interior transmission…

Analysis of PDEs · Mathematics 2015-06-16 David Finch , Kyle S. Hickmann

We consider the inverse problem of determining different type of information about a diffusion process, described by ordinary or fractional diffusion equations stated on a bounded domain, like the density of the medium or the velocity field…

Analysis of PDEs · Mathematics 2019-07-05 Yavar Kian , Zhiyuan Li , Yikan Liu , Masahiro Yamamoto

A lattice Boltzmann model is considered in which the speed of sound can be varied independently of the other parameters. The range over which the speed of sound can be varied is investigated and good agreement is found between simulations…

Fluid Dynamics · Physics 2007-07-18 J. M. Buick , J. A. Cosgrove

We present an alternative method for determining the sound velocity in atomic Bose-Einstein condensates, based on thermodynamic global variables. The total number of trapped atoms was as a function of temperature carefully studied across…

Accurate simulations of sound propagation in narrow geometries need to account for viscous and thermal losses. In this respect, effective boundary conditions that model viscothermal losses in frequency-domain acoustics have recently gained…

Computational Physics · Physics 2024-10-24 Linus Hägg , Martin Berggren

We study the inverse problem of determining both the source of a wave and its speed inside a medium from measurements of the solution of the wave equation on the boundary. This problem arises in photoacoustic and thermoacoustic tomography,…

Analysis of PDEs · Mathematics 2019-06-18 Christina Knox , Amir Moradifam

It is shown that thermal fluctuations present in a simple non-degenerate relativistic fluid satisfy a wave equation in the Euler regime. The characteristic propagation speeds are calculated and the classical expression for the speed of…

General Relativity and Quantum Cosmology · Physics 2009-05-19 A. Sandoval-Villalbazo , D. Brun

We study the fixed angle inverse scattering problem of determining a sound speed from scattering measurements corresponding to a single incident wave. The main result shows that a sound speed close to constant can be stably determined by…

Analysis of PDEs · Mathematics 2023-04-25 Shiqi Ma , Leyter Potenciano-Machado , Mikko Salo

We consider an inverse boundary value problem for a model time-harmonic equation of acoustic tomography of moving fluid with variable current velocity, sound speed, density and absorption. In the present article it is assumed that at fixed…

Analysis of PDEs · Mathematics 2017-02-14 Alexey Agaltsov

We explore Thermoacoustic Tomography with circular integrating detectors assuming variable, smooth wave speed. We show that the measurement operator in this case is a Fourier Integral Operator and examine how the singularities in initial…

Analysis of PDEs · Mathematics 2019-07-03 Chase Mathison

We investigate the problem of recovering the initial displacement f for a solution u of a linear, isotropic, non-homogeneous elastic wave equation, given measurements of u on [0,T] x \partial \Omega, where \Omega\subset\R^3 is some bounded…

Analysis of PDEs · Mathematics 2015-05-28 Justin Tittelfitz

The acoustic wave-propagation without mean flow and heat flux can be described in terms of velocity and pressure by the compressible nonlinear Navier-Stokes equations, where boundary layers appear at walls due to the viscosity and a…

Analysis of PDEs · Mathematics 2017-01-10 Anastasia Thoens-Zueva , Kersten Schmidt , Adrien Semin

The coupling between mechanical and thermal properties due to thermal expansion complicates the problem of measuring frequency-dependent thermoviscoelastic properties, in particular for highly viscous liquids. A simplification arises if…

Soft Condensed Matter · Physics 2009-11-13 Tage Christensen , Jeppe C. Dyre

We study linear damped and viscoelastic wave equations evolving on a bounded domain. For both models, we assume that waves are subject to an inhomogeneous Neumann boundary condition on a portion of the domain's boundary. The analysis of…

Analysis of PDEs · Mathematics 2024-10-15 Türker Özsarı , İdem Susuzlu

In this paper, we present a mathematical model and analysis for a new experimental method [Bureau and al., arXiv:2409.13901, 2024] for effective sound velocity estimation in medical ultrasound imaging. We perform a detailed analysis of the…

Analysis of PDEs · Mathematics 2025-05-13 Josselin Garnier , Laure Giovangigli , Quentin Goepfert , Pierre Millien

This study focuses on the Rijke tube problem, which includes features relevant to the modeling of thermoacoustic coupling in reactive flows: a compact acoustic source, an empirical model for the heat source, and nonlinearities. This…

Computational Physics · Physics 2015-08-21 Taraneh Sayadi , Vincent Le Chenadec , Peter Schmid , Franck Richecoeur , Marc Massot

We consider an inverse problem arising in nonlinear ultrasound imaging. The propagation of ultrasound waves is modeled by a quasilinear wave equation. We make measurements at the boundary of the medium encoded in the Dirichlet-to-Neumann…

Analysis of PDEs · Mathematics 2022-03-08 Gunther Uhlmann , Yang Zhang

We consider the inverse source problem arising in thermo- and photo-acoustic tomography. It consists in reconstructing the initial pressure from the boundary measurements of the acoustic wave. Our goal is to extend versatile time reversal…

Analysis of PDEs · Mathematics 2015-11-13 Linh V. Nguyen , Leonid Kunyansky

In this paper, we consider the travel time tomography problem for conformal metrics on a bounded domain, which seeks to determine the conformal factor of the metric from the lengths of geodesics joining boundary points. We establish forward…

Differential Geometry · Mathematics 2024-05-28 Ashwin Tarikere , Hanming Zhou