Fast solvers for the high-order FEM simplicial de Rham complex: Extended edition

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Brubeck, Pablo D., Farrell, Patrick E., Kirby, Robert C., Parker, Charles
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910054946439168
author Brubeck, Pablo D.
Farrell, Patrick E.
Kirby, Robert C.
Parker, Charles
author_facet Brubeck, Pablo D.
Farrell, Patrick E.
Kirby, Robert C.
Parker, Charles
contents We present new finite elements for solving the Riesz maps of the de Rham complex on triangular and tetrahedral meshes at high order. The finite elements discretize the same spaces as usual, but with different basis functions, so that the resulting matrices have desirable properties. These properties mean that we can solve the Riesz maps to a given accuracy in a $p$-robust number of iterations with $\mathcal{O}(p^6)$ flops in three dimensions, rather than the naïve $\mathcal{O}(p^9)$ flops. The degrees of freedom build upon an idea of Demkowicz et al., and consist of integral moments on an equilateral reference simplex with respect to a numerically computed polynomial basis that is orthogonal in two different inner products. As a result, the interior-interface and interior-interior couplings are provably weak, and we devise a preconditioning strategy by neglecting them. The combination of this approach with a space decomposition method on vertex and edge star patches allows us to efficiently solve the canonical Riesz maps at high order. We apply this to solving the Hodge Laplacians of the de Rham complex with novel augmented Lagrangian preconditioners.
format Preprint
id arxiv_https___arxiv_org_abs_2506_17406
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Fast solvers for the high-order FEM simplicial de Rham complex: Extended edition
Brubeck, Pablo D.
Farrell, Patrick E.
Kirby, Robert C.
Parker, Charles
Numerical Analysis
65F08, 65N35, 65N55
We present new finite elements for solving the Riesz maps of the de Rham complex on triangular and tetrahedral meshes at high order. The finite elements discretize the same spaces as usual, but with different basis functions, so that the resulting matrices have desirable properties. These properties mean that we can solve the Riesz maps to a given accuracy in a $p$-robust number of iterations with $\mathcal{O}(p^6)$ flops in three dimensions, rather than the naïve $\mathcal{O}(p^9)$ flops. The degrees of freedom build upon an idea of Demkowicz et al., and consist of integral moments on an equilateral reference simplex with respect to a numerically computed polynomial basis that is orthogonal in two different inner products. As a result, the interior-interface and interior-interior couplings are provably weak, and we devise a preconditioning strategy by neglecting them. The combination of this approach with a space decomposition method on vertex and edge star patches allows us to efficiently solve the canonical Riesz maps at high order. We apply this to solving the Hodge Laplacians of the de Rham complex with novel augmented Lagrangian preconditioners.
title Fast solvers for the high-order FEM simplicial de Rham complex: Extended edition
topic Numerical Analysis
65F08, 65N35, 65N55
url https://arxiv.org/abs/2506.17406