Local absorbing boundary conditions on fixed domains give order-one errors for high-frequency waves

J Galkowski, D Lafontaine… - IMA Journal of Numerical …, 2024 - academic.oup.com
We consider approximating the solution of the Helmholtz exterior Dirichlet problem for a
nontrapping obstacle, with boundary data coming from plane-wave incidence, by the …

Sharp Preasymptotic Error Bounds for the Helmholtz -FEM

J Galkowski, EA Spence - SIAM Journal on Numerical Analysis, 2025 - SIAM
In the analysis of the-version of the finite-element method (FEM), with fixed polynomial
degree, applied to the Helmholtz equation with wavenumber, the asymptotic regime is when …

Wavenumber-explicit stability and convergence analysis of hp finite element discretizations of Helmholtz problems in piecewise smooth media

M Bernkopf, T Chaumont-Frelet, JM Melenk - arXiv preprint arXiv …, 2022 - arxiv.org
We present a wavenumber-explicit convergence analysis of the hp finite element method
applied to a class of heterogeneous Helmholtz problems with piecewise analytic coefficients …

The -FEM applied to the Helmholtz equation with PML truncation does not suffer from the pollution effect

J Galkowski, D Lafontaine, EA Spence… - arXiv preprint arXiv …, 2022 - arxiv.org
We consider approximation of the variable-coefficient Helmholtz equation in the exterior of a
Dirichlet obstacle using perfectly-matched-layer (PML) truncation; it is well known that this …

Convergence of parallel overlapping domain decomposition methods for the Helmholtz equation

S Gong, MJ Gander, IG Graham, D Lafontaine… - Numerische …, 2022 - Springer
We analyse parallel overlapping Schwarz domain decomposition methods for the Helmholtz
equation, where the exchange of information between subdomains is achieved using first …

Wavenumber-explicit parametric holomorphy of Helmholtz solutions in the context of uncertainty quantification

EA Spence, J Wunsch - SIAM/ASA Journal on Uncertainty Quantification, 2023 - SIAM
A crucial role in the theory of uncertainty quantification (UQ) of PDEs is played by the
regularity of the solution with respect to the stochastic parameters; indeed, a key property …

The scattering phase: seen at last

J Galkowski, P Marchand, J Wang, M Zworski - SIAM Journal on Applied …, 2024 - SIAM
The scattering phase, defined as where is the (unitary) scattering matrix, is the analogue of
the counting function for eigenvalues when dealing with exterior domains and is closely …

A simple proof that the hp-FEM does not suffer from the pollution effect for the constant-coefficient full-space Helmholtz equation

EA Spence - Advances in Computational Mathematics, 2023 - Springer
In d dimensions, accurately approximating an arbitrary function oscillating with frequency≲ k
requires∼ kd degrees of freedom. A numerical method for solving the Helmholtz equation …

Frequency-Explicit Shape Holomorphy in Uncertainty Quantification for Acoustic Scattering

R Hiptmair, C Schwab, EA Spence - arXiv preprint arXiv:2408.01194, 2024 - arxiv.org
We consider frequency-domain acoustic scattering at a homogeneous star-shaped
penetrable obstacle, whose shape is uncertain and modelled via a radial spectral …

Wavenumber-explicit stability and convergence analysis of ℎ𝑝 finite element discretizations of Helmholtz problems in piecewise smooth media

M Bernkopf, T Chaumont-Frelet, J Melenk - Mathematics of Computation, 2024 - ams.org
We present a wavenumber-explicit convergence analysis of the $ hp $ Finite Element
Method applied to a class of heterogeneous Helmholtz problems with piecewise analytic …