Mortar Element Methods for Parabolic Problems

Abstract

In this article a standard mortar finite element method and a mortar element method with Lagrange multiplier are used for spatial discretization of a class of parabolic initial-boundary value problems. Optimal error estimates in L-infinity(L-2) and L-infinity (H-1)-norms for semidiscrete methods for both the cases are established. The key feature that we have adopted here is to introduce a modified elliptic projection. In the standard mortar element method, a completely discrete scheme using backward Euler scheme is discussed and optimal error estimates are derived. The results of numerical experiments support the theoretical results obtained in this article. (C) 2008 . Numer Methods Partial Differential Eq 24: 1460-1484, 2008