An explicit P1 finite element scheme for Maxwell's equations with constant permittivity in a boundary neighborhood

Abstract

This paper is devoted to the complete convergence study of the finite-element approximation of Maxwell's equations in the case where the magnetic permeability is constant. Standard linear finite elements for the space discretization are combined with a well-known explicit finite-difference scheme for the time discretization. The analysis applies to the particular case where the dielectric permittivity has a constant value outside a sub-domain, whose closure does not intersect the boundary of the problem-definition domain. Optimal convergence results are established in natural norms under reasonable assumptions, provided a classical CFL condition holds. A numerical validation of the theoretical results is provided.

This version consists of 38 pages. It incorporates an additional section containing results of numerical experimentation, which validate the theoretical analysis