Misc,

Space-time discontinuous Galerkin approximation of acoustic waves with point singularities

, , , and .
(2020)cite arxiv:2002.11575Comment: 38 pages, 8 figures.

Abstract

We develop a convergence theory of space-time discretizations for the linear, 2nd-order wave equation in polygonal domains $Ømega\subsetR^2$, possibly occupied by piecewise homogeneous media with different propagation speeds. Building on an unconditionally stable space-time DG formulation developed in Moiola, Perugia 2018, we (a) prove optimal convergence rates for the space-time scheme with local isotropic corner mesh refinement on the spatial domain, and (b) demonstrate numerically optimal convergence rates of a suitable sparse space-time version of the DG scheme. The latter scheme is based on the so-called combination formula, in conjunction with a family of anisotropic space-time DG-discretizations. It results in optimal-order convergent schemes, also in domains with corners, with a number of degrees of freedom that scales essentially like the DG solution of one stationary elliptic problem in $Ømega$ on the finest spatial grid. Numerical experiments for both smooth and singular solutions support convergence rate optimality on spatially refined meshes of the full and sparse space-time DG schemes.

Tags

Users

  • @dagon
  • @dblp

Comments and Reviews