Massively parallel Schwarz methods for the high frequency Helmholtz equation

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Xie, Yan, Gong, Shihua, Graham, Ivan G., Spence, Euan A., Zhang, Chen-Song
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918317472612352
author Xie, Yan
Gong, Shihua
Graham, Ivan G.
Spence, Euan A.
Zhang, Chen-Song
author_facet Xie, Yan
Gong, Shihua
Graham, Ivan G.
Spence, Euan A.
Zhang, Chen-Song
contents We investigate the parallel one-level overlapping Schwarz method for solving finite element discretization of high-frequency Helmholtz equations. The resulting linear systems are large, indefinite, ill-conditioned, and complex-valued. We present a practical variant of the restricted additive Schwarz method with Perfectly Matched Layer transmission conditions (RAS-PML), which was originally analyzed in a theoretical setting in {\tt arXiv:2404.02156}, with some numerical experiments given in {\tt arXiv:2408.16580}. In our algorithm, the width of the overlap and the additional PML layer on each subdomain is allowed to decrease with $\mathcal{O}(k^{-1} \log(k))$, as the frequency $k \rightarrow \infty$, and this is observed to ensure good convergence while avoiding excessive communication. In experiments, the proposed method achieves $\mathcal{O}(k^d)$ parallel scalability under Cartesian domain decomposition and exhibits $\mathcal{O}(k)$ iteration counts and convergence time for $d$-dimensional Helmholtz problems ($d = 2,3$) as $k$ increases. In this preliminary note we restrict to experiments on 2D problems with constant wave speed. Details, analysis and extensions to variable wavespeed and 3D will be given in future work.
format Preprint
id arxiv_https___arxiv_org_abs_2602_00735
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Massively parallel Schwarz methods for the high frequency Helmholtz equation
Xie, Yan
Gong, Shihua
Graham, Ivan G.
Spence, Euan A.
Zhang, Chen-Song
Numerical Analysis
We investigate the parallel one-level overlapping Schwarz method for solving finite element discretization of high-frequency Helmholtz equations. The resulting linear systems are large, indefinite, ill-conditioned, and complex-valued. We present a practical variant of the restricted additive Schwarz method with Perfectly Matched Layer transmission conditions (RAS-PML), which was originally analyzed in a theoretical setting in {\tt arXiv:2404.02156}, with some numerical experiments given in {\tt arXiv:2408.16580}. In our algorithm, the width of the overlap and the additional PML layer on each subdomain is allowed to decrease with $\mathcal{O}(k^{-1} \log(k))$, as the frequency $k \rightarrow \infty$, and this is observed to ensure good convergence while avoiding excessive communication. In experiments, the proposed method achieves $\mathcal{O}(k^d)$ parallel scalability under Cartesian domain decomposition and exhibits $\mathcal{O}(k)$ iteration counts and convergence time for $d$-dimensional Helmholtz problems ($d = 2,3$) as $k$ increases. In this preliminary note we restrict to experiments on 2D problems with constant wave speed. Details, analysis and extensions to variable wavespeed and 3D will be given in future work.
title Massively parallel Schwarz methods for the high frequency Helmholtz equation
topic Numerical Analysis
url https://arxiv.org/abs/2602.00735