Non-conforming high order approximations of the elastodynamics equation

In this paper we formulate and analyze two non-conforming high order strategies for the approximation of elastic wave problems in heterogeneous media, namely the Mortar Spectral Element Method and the Discontinuous Galerkin Spectral Element Method. Starting from a common variational formulation we make a full comparison of the two techniques from the points of view of accuracy, convergence, grid dispersion and stability.