Wavenumber-explicit convergence of the hp-FEM for the full-space heterogeneous Helmholtz equation with smooth coefficients

David Lafontaine, Euan A. Spence, Jared Wunsch

Research output: Contribution to journalArticlepeer-review

Abstract

A convergence theory for the hp-FEM applied to a variety of constant-coefficient Helmholtz problems was pioneered in the papers [35], [36], [15], [34]. This theory shows that, if the solution operator is bounded polynomially in the wavenumber k, then the Galerkin method is quasioptimal provided that hk/p≤C 1 and p≥C 2log⁡k, where C 1 is sufficiently small, C 2 is sufficiently large, and both are independent of k,h, and p. The significance of this result is that if hk/p=C 1 and p=C 2log⁡k, then quasioptimality is achieved with the total number of degrees of freedom proportional to k d; i.e., the hp-FEM does not suffer from the pollution effect. This paper proves the analogous quasioptimality result for the heterogeneous (i.e. variable-coefficient) Helmholtz equation, posed in R d, d=2,3, with the Sommerfeld radiation condition at infinity, and C coefficients. We also prove a bound on the relative error of the Galerkin solution in the particular case of the plane-wave scattering problem. These are the first ever results on the wavenumber-explicit convergence of the hp-FEM for the Helmholtz equation with variable coefficients.

Original languageEnglish
Pages (from-to)59-69
Number of pages11
JournalComputers & Mathematics with Applications
Volume113
Early online date18 Mar 2022
DOIs
Publication statusPublished - 1 May 2022

Keywords

  • Helmholtz equation
  • High frequency
  • Pollution effect
  • hp-FEM

ASJC Scopus subject areas

  • Modelling and Simulation
  • Computational Theory and Mathematics
  • Computational Mathematics

Fingerprint

Dive into the research topics of 'Wavenumber-explicit convergence of the hp-FEM for the full-space heterogeneous Helmholtz equation with smooth coefficients'. Together they form a unique fingerprint.

Cite this