A local discontinuous Galerkin gradient discretization method for linear and quasilinear elliptic equations

TL;DR

This paper introduces a local discontinuous Galerkin gradient discretization method for elliptic equations, which adaptively refines solutions in high gradient regions, proving convergence and analyzing errors with numerical validation.

Contribution

The paper presents a novel local scheme based on a coarse grid that successively improves solutions in high gradient areas, with proven convergence for linear and quasilinear equations.

Findings

Convergence proven under minimal regularity assumptions

Higher order accuracy for boundary condition errors

Numerical experiments confirm theoretical results and improved local accuracy

Abstract

A local weighted discontinuous Galerkin gradient discretization method for solving elliptic equations is introduced. The local scheme is based on a coarse grid and successively improves the solution solving a sequence of local elliptic problems in high gradient regions. Using the gradient discretization framework we prove convergence of the scheme for linear and quasilinear equations under minimal regularity assumptions. The error due to artificial boundary conditions is also analyzed, shown to be of higher order and shown to depend only locally on the regularity of the solution. Numerical experiments illustrate our theoretical findings and the local method's accuracy is compared against the non local approach