Fast tensor product Schwarz smoothers for high-order discontinuous Galerkin methods

We discuss the efficient implementation of powerful domain decomposition smoothers for multigrid methods for high-order discontinuous Galerkin (DG) finite element methods. In particular, we study the inversion of matrices associated to mesh cells and to the patches around a vertex, respectively, in...

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Hauptverfasser: Witte, Julius (VerfasserIn) , Arndt, Daniel (VerfasserIn) , Kanschat, Guido (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 2021
In: Computational methods in applied mathematics
Year: 2021, Jahrgang: 21, Heft: 3, Pages: 709-728
ISSN:1609-9389
DOI:10.1515/cmam-2020-0078
Online-Zugang:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1515/cmam-2020-0078
Verlag, lizenzpflichtig, Volltext: https://www.degruyterbrill.com/document/doi/10.1515/cmam-2020-0078/html
Volltext
Verfasserangaben:Julius Witte, Daniel Arndt, and Guido Kanschat
Beschreibung
Zusammenfassung:We discuss the efficient implementation of powerful domain decomposition smoothers for multigrid methods for high-order discontinuous Galerkin (DG) finite element methods. In particular, we study the inversion of matrices associated to mesh cells and to the patches around a vertex, respectively, in order to obtain fast local solvers for additive and multiplicative subspace correction methods. The effort of inverting local matrices for tensor product polynomials of degree k is reduced from 𝒪 ⁢ ( k 3 ⁢ d ) {\mathcal{O}(k^{3d})} to 𝒪 ⁢ ( d ⁢ k d + 1 ) {\mathcal{O}(dk^{d+1})} by exploiting the separability of the differential operator and resulting low rank representation of its inverse as a prototype for more general low rank representations in space dimension d .
Beschreibung: Veröffentlicht von De Gruyter 11. November 2020
Gesehen am 29.09.2021
Beschreibung:Online Resource
ISSN:1609-9389
DOI:10.1515/cmam-2020-0078