Convergence theory for two-level hybrid Schwarz preconditioners for high-frequency Helmholtz problems

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Galkowski, Jeffrey, Spence, Euan A.
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866909807506620416
author Galkowski, Jeffrey
Spence, Euan A.
author_facet Galkowski, Jeffrey
Spence, Euan A.
contents We give a novel convergence theory for two-level hybrid Schwarz domain-decomposition (DD) methods for finite-element discretisations of the high-frequency Helmholtz equation. This theory gives sufficient conditions for the preconditioned matrix to be close to the identity, and covers DD subdomains of arbitrary size, arbitrary absorbing layers/boundary conditions on both the global and local Helmholtz problems, and coarse spaces not necessarily related to the subdomains. The assumptions on the coarse space are satisfied by the approximation spaces using problem-adapted basis functions that have been recently analysed as coarse spaces for the Helmholtz equation, as well as all spaces that are known to be quasi-optimal via a Schatz-type argument. As an example, we apply this theory when the coarse space consists of piecewise polynomials; these are then the first rigorous convergence results about a two-level Schwarz preconditioner applied to the high-frequency Helmholtz equation with a coarse space that does not consist of problem-adapted basis functions.
format Preprint
id arxiv_https___arxiv_org_abs_2501_11060
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Convergence theory for two-level hybrid Schwarz preconditioners for high-frequency Helmholtz problems
Galkowski, Jeffrey
Spence, Euan A.
Numerical Analysis
We give a novel convergence theory for two-level hybrid Schwarz domain-decomposition (DD) methods for finite-element discretisations of the high-frequency Helmholtz equation. This theory gives sufficient conditions for the preconditioned matrix to be close to the identity, and covers DD subdomains of arbitrary size, arbitrary absorbing layers/boundary conditions on both the global and local Helmholtz problems, and coarse spaces not necessarily related to the subdomains. The assumptions on the coarse space are satisfied by the approximation spaces using problem-adapted basis functions that have been recently analysed as coarse spaces for the Helmholtz equation, as well as all spaces that are known to be quasi-optimal via a Schatz-type argument. As an example, we apply this theory when the coarse space consists of piecewise polynomials; these are then the first rigorous convergence results about a two-level Schwarz preconditioner applied to the high-frequency Helmholtz equation with a coarse space that does not consist of problem-adapted basis functions.
title Convergence theory for two-level hybrid Schwarz preconditioners for high-frequency Helmholtz problems
topic Numerical Analysis
url https://arxiv.org/abs/2501.11060