Can coercive formulations lead to fast and accurate solution of the Helmholtz equation?

Ganesh C. Diwan, Andrea Moiola, Euan A. Spence

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

A new, coercive formulation of the Helmholtz equation was introduced in Moiola and Spence (2014). In this paper we investigate h-version Galerkin discretisations of this formulation, and the iterative solution of the resulting linear systems. We find that the coercive formulation behaves similarly to the standard formulation in terms of the pollution effect (i.e. to maintain accuracy as k→∞ h must decrease with k at the same rate as for the standard formulation). We prove k-explicit bounds on the number of GMRES iterations required to solve the linear system of the new formulation when it is preconditioned with a prescribed symmetric positive-definite matrix. Even though the number of iterations grows with k, these are the first such rigorous bounds on the number of GMRES iterations for a preconditioned formulation of the Helmholtz equation, where the preconditioner is a symmetric positive-definite matrix.

Original languageEnglish
Pages (from-to)110-131
Number of pages22
JournalJournal of Computational and Applied Mathematics
Volume352
Early online date6 Dec 2018
DOIs
Publication statusPublished - 15 May 2019

Keywords

  • math.NA
  • 35J05, 65N30, 65F10
  • Finite element method
  • GMRES
  • Helmholtz equation
  • Wavenumber-explicit analysis
  • Coercive variational formulation
  • Pollution effect

ASJC Scopus subject areas

  • Computational Mathematics
  • Applied Mathematics

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