4 papers
Helmholtz quasi-resonances are unstable under most single-signed perturbations of the wave speed
Euan A. Spence, Jared Wunsch, Yuzhou Zou
We consider Helmholtz problems with a perturbed wave speed, where the single-signed perturbation is linear in a parameter . Both the wave speed and the perturbation are allowed…
Scattering by finely-layered obstacles: frequency-explicit bounds and homogenization
Théophile Chaumont-Frelet, Euan A. Spence
We consider the scalar Helmholtz equation with variable, discontinuous coefficients, modelling transmission of acoustic waves through an anisotropic penetrable obstacle. We first p…
High-frequency estimates on boundary integral operators for the Helmholtz exterior Neumann problem
Jeffrey Galkowski, Pierre Marchand, Euan A. Spence
We study a commonly-used second-kind boundary-integral equation for solving the Helmholtz exterior Neumann problem at high frequency, where, writing for the boundary of the obs…
Recent Results on Domain Decomposition Preconditioning for the High-frequency Helmholtz Equation using Absorption
I. G. Graham, E. A. Spence, E. Vainikko
In this paper we present an overview of recent progress on the development and analysis of domain decomposition preconditioners for discretised Helmholtz problems, where the precon…