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A broad class of nonlinear acoustic wave models possess a Hamiltonian structure in their dissipation-free limit and a gradient flow structure for their dissipative dynamics. This structure may be exploited to design numerical methods which…

Numerical Analysis · Mathematics 2024-07-23 William Barham , Philip J. Morrison

The goal of this work is to improve focusing of high-intensity ultrasound by modifying the geometry of acoustic lenses through shape optimization. The shape optimization problem is formulated by introducing a tracking-type cost functional…

Optimization and Control · Mathematics 2017-12-15 Markus Muhr , Vanja Nikolić , Barbara Wohlmuth , Linus Wunderlich

In this paper, we suggest a new Heterogeneous Multiscale Method (HMM) for the (time-harmonic) Maxwell scattering problem with high contrast. The method is constructed for a setting as in Bouchitt\'e, Bourel and Felbacq (C.R. Math. Acad.…

Numerical Analysis · Mathematics 2017-10-27 Barbara Verfürth

In this work, we propose multicontinuum splitting schemes for the wave equation with a high-contrast coefficient, extending our previous research on multiscale flow problems. The proposed approach consists of two main parts: decomposing the…

Numerical Analysis · Mathematics 2025-06-03 Mohsen Alshahrani , Buzheng Shan

Biharmonic wave equations are of importance to various applications including thin plate analyses. In this work, the numerical approximation of their solutions by a $C^1$-conforming in space and time finite element approach is proposed and…

Numerical Analysis · Mathematics 2021-07-09 Markus Bause , Maria Lymbery , Kevin Osthues

This Letter brings together two topics that, until now, have been the focus of intense but non-overlapping research efforts. The first concerns high harmonic generation in solids, which occurs when intense light field excites highly…

Strongly Correlated Electrons · Physics 2022-04-06 R. E. F. Silva , Igor V. Blinov , Alexey N. Rubtsov , O. Smirnova , M. Ivanov

Efficient time integration methods based on operator splitting are introduced for the Westervelt equation, a nonlinear damped wave equation that arises in nonlinear acoustics as mathematical model for the propagation of sound waves in high…

Numerical Analysis · Mathematics 2013-11-07 Barbara Kaltenbacher , Vanja Nikolic , Mechthild Thalhammer

In this paper, we suggest a new heterogeneous multiscale method (HMM) for the time-harmonic Maxwell equations in locally periodic media. The method is constructed by using a divergence-regularization in one of the cell problems. This allows…

Numerical Analysis · Mathematics 2015-09-15 Patrick Henning , Mario Ohlberger , Barbara Verfürth

The Westervelt equation is a model for the propagation of finite amplitude ultrasound. The method of discrete exterior calculus can be used to solve this equation numerically. A significant advantage of this method is that it can be used to…

Numerical Analysis · Mathematics 2010-01-14 Zheng Xie , Yujie Ma

Monodisperse microbubble ultrasound contrast agents have been proposed to further increase the signal-to-noise-ratio of contrast enhanced ultrasound imaging. Here, the sensitivity of a polydisperse preclinical agent was compared…

Medical Physics · Physics 2018-06-13 Tim Segers , Pieter Kruizinga , Maarten Kok , Guillaume Lajoinie , Nico de Jong , Michel Versluis

We deal with the linearized model of the acoustic wave propagation generated by small bubbles in the harmonic regime. We estimate the waves generated by a cluster of $M$ small bubbles, distributed in a bounded domain $\Omega$, with relative…

Analysis of PDEs · Mathematics 2019-06-17 Habib Ammari , Durga Prasad Challa , Anupam Pal Choudhury , Mourad Sini

We are concerned with the reconstruction of inclusions in elastic bodies based on measurements from a laboratory experiment. In doing so, we solve the inverse problem of the time-harmonic elastic wave equation, in contrast to the stationary…

Analysis of PDEs · Mathematics 2026-05-21 Sarah Eberle-Blick , Jochen Moll

In this paper we propose a multiscale method for the acoustic wave equation in highly oscillatory media. We use a higher-order extension of the localized orthogonal decomposition method combined with a higher-order time stepping scheme and…

Numerical Analysis · Mathematics 2024-07-23 Felix Krumbiegel , Roland Maier

Arbitrary high order numerical methods for time-harmonic acoustic scattering problems originally defined on unbounded domains are constructed. This is done by coupling recently developed high order local absorbing boundary conditions (ABCs)…

Numerical Analysis · Mathematics 2020-06-17 Vianey Villamizar , Dane Grundvig , Otilio Rojas , Sebastian Acosta

We develop and analyze a new approach for simultaneously computing multiple solutions to the Helmholtz equation for different frequencies and different forcing functions. The new Multi-Frequency WaveHoltz (MFWH) algorithm is an extension of…

An alternative approach to ultrasound computed tomography (USCT) for medical imaging is proposed, with the intent to (i) shorten acquisition time for devices with a large number of emitters, (ii) eliminate the calibration step, and (iii)…

Medical Physics · Physics 2022-01-25 Ines Elisa Ulrich , Christian Boehm , Andrea Zunino , Cyrill Bösch , Andreas Fichtner

We study the time-domain acoustic wave propagation in the presence of a micro-bubble. This micro-bubble is characterized by a mass density and bulk modulus which are both very small as compared to the ones of the background vacuum. The goal…

Analysis of PDEs · Mathematics 2023-12-13 Arpan Mukherjee , Mourad Sini

Results are presented from numerical modeling of the effect of the inhomogeneity of the ion background on the complicated spatiotemporal dynamics of an electron beam with a virtual cathode in plane geometry. The possibility is demonstrated…

Plasma Physics · Physics 2015-06-26 A. A. Koronovskii , A. E. Hramov

The statistical problem of parameter estimation in partially observed hypoelliptic diffusion processes is naturally occurring in many applications. However, due to the noise structure, where the noise components of the different coordinates…

Methodology · Statistics 2018-11-13 Susanne Ditlevsen , Adeline Samson

A novel approach to computing time-harmonic solutions of Maxwell's equations by time-domain simulations is presented. The method, EM-WaveHoltz, results in a positive definite system of equations which makes it amenable to iterative solution…

Numerical Analysis · Mathematics 2022-08-17 Zhichao Peng , Daniel Appelö