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We solve the one-dimensional Helmholtz equation in several scenarios using the quantum annealer provided by the D-Wave systems within a pseudospectral scheme, where its solution is encoded into certain set of suitable basis functions. We…

Quantum Physics · Physics 2025-07-21 Aigerim Bazarkhanova , Alejandro J. Castro , Antonio A. Valido

The Helmholtz equation is fundamental to wave modeling in acoustics, electromagnetics, and seismic imaging, yet high-frequency regimes remain challenging due to the ``pollution effect''. We propose FD-MGDL, an adaptive framework integrating…

Numerical Analysis · Mathematics 2026-02-25 Peiyao Zhao , Rui Wang , Tingting Wu , Yuesheng Xu

The problem of scattering of harmonic plane acoustic waves by fluid spheroids (prolate and oblate) is addressed from an analytical approach. Mathematically, it consists in solving the Helmholtz equation in an unbounded domain with…

Computational Physics · Physics 2019-12-04 Juan D. González , Edmundo F. Lavia , Silvia Blanc

We survey functional analytic methods for studying subwavelength resonator systems. In particular, rigorous discrete approximations of Helmholtz scattering problems are derived in an asymptotic subwavelength regime. This is achieved by…

Analysis of PDEs · Mathematics 2024-10-02 Habib Ammari , Bryn Davies , Erik Orvehed Hiltunen

In this work, we aim to establish a detailed description of the physical mechanisms of intrinsic thermoacoustic modes and their interplay with duct acoustic modes. The biglobal linear stability analysis of an anchored laminar flame in an…

Fluid Dynamics · Physics 2024-09-26 Lu Chen , Yu Lv

This paper is concerned with an inverse wavenumber/frequency-dependent source problem for the Helmholtz equation. In two and three dimensions, the unknown source term is supposed to be compactly supported in spatial variables but…

Numerical Analysis · Mathematics 2024-04-02 Mengjie Zhao , Suliang Si , Guanghui Hu

Solution of Helmholtz equation with impedance boundary condition on finite interval is equivalently reformulated as steady state of initial boundary value problem for first order hyperbolic system of partial differential equations.…

Numerical Analysis · Mathematics 2018-06-19 Ramaz Botchorishvili , Tamar Janelidze

Nonlinear ultrasound imaging leverages harmonic wave generation to enhance contrast and spatial resolution beyond the capabilities of conventional linear techniques. This behavior is commonly modeled by the Westervelt equation, which…

Analysis of PDEs · Mathematics 2026-05-25 Benjamin Rainer , Barbara Kaltenbacher

We consider the application of the WaveHoltz iteration to time-harmonic elastic wave equations with energy conserving boundary conditions. The original WaveHoltz iteration for acoustic Helmholtz problems is a fixed-point iteration that…

Numerical Analysis · Mathematics 2022-09-28 Daniel Appelö , Fortino Garcia , Allen Alvarez Loya , Olof Runborg

In this work we consider the computational approximation of a unique continuation problem for the Helmholtz equation using a stabilized finite element method. First conditional stability estimates are derived for which, under a convexity…

Numerical Analysis · Mathematics 2018-10-29 Erik Burman , Mihai Nechita , Lauri Oksanen

In this paper, an efficient solver for the Helmholtz equation using a noval approximation space is developed. The ingradients of the method include the approximation space recently proposed, a discontinuous Galerkin scheme extensively used,…

Numerical Analysis · Mathematics 2025-12-11 Shuhai Zhao

Context. The study of linear waves and instabilities is necessary to understand the physical evolution of an atmosphere, and can provide physical interpretation of the complex flows found in simulations performed using Global Circulation…

Earth and Planetary Astrophysics · Physics 2019-10-16 Florian Debras , Nathan Mayne , Isabelle Baraffe , Tom Goffrey , John Thuburn

In this paper, we consider the resonance problem for the cubic nonlinear Helmholtz equation in the subwavelength regime. We derive a discrete model for approximating the subwavelength resonances of finite systems of high-contrast resonators…

Mathematical Physics · Physics 2025-04-17 Habib Ammari , Thea Kosche

We develop the effective non-Hermitian Hamiltonian approach for open systems with Neumann boundary conditions. The approach can be used for calculating the scattering matrix and the scattering function in open resonator-waveguide systems.…

Quantum Physics · Physics 2015-04-14 Dmitrii N. Maksimov , Almas F. Sadreev , Alina A. Lyapina , Artem S. Pilipchuk

Trefftz methods are finite element-type schemes whose test and trial functions are (locally) solutions of the targeted differential equation. They are particularly popular for time-harmonic wave problems, as their trial spaces contain…

Numerical Analysis · Mathematics 2023-10-11 Ralf Hiptmair , Andrea Moiola , Ilaria Perugia

We discuss the implementation details and the numerical performance of the recently introduced nonconforming Trefftz virtual element method for the 2D Helmholtz problem. In particular, we present a strategy to significantly reduce the…

Numerical Analysis · Mathematics 2019-02-20 L. Mascotto , I. Perugia , A. Pichler

We develop a stability index for the travelling waves of non-linear reaction diffusion equations using the geometric phase induced on the Hopf bundle $S^{2n-1} \subset \mathbb{C}^n$. This can be viewed as an alternative formulation of the…

Dynamical Systems · Mathematics 2016-02-24 Colin J. Grudzien , Tom J. Bridges , Christopher K. R. T. Jones

In this paper, we study the nonlinear periodic Westervelt equation with excitations located within a bounded domain in $\mathbb{R}^d$, where $d \in \{2,3\}$, subject to Robin boundary conditions. This problem is of particular interest for…

Analysis of PDEs · Mathematics 2026-01-06 Benjamin Rainer , Barbara Kaltenbacher

This paper concerns the inverse source problem for the time-harmonic wave equation in a one dimensional domain. The goal is to determine the source function from the boundary measurements. The problem is challenging due to complexity of the…

Analysis of PDEs · Mathematics 2020-04-08 Elham Sohrabi

In this paper, we develop an accurate and efficient framework for computing subwavelength guided modes in high-contrast periodic media with line defects, based on a tight-binding approximation. The physical problem is formulated as an…

Mathematical Physics · Physics 2026-01-21 Habib Ammari , Erik Orvehed Hiltunen , Ping Liu , Borui Miao , Yi Zhu