Superconvergent Recovery of Rectangular Edge Finite Element Approximation by Local Symmetry Projection

Abstract

A new recovery method of rectangular edge finite element approximation for Maxwell's equations is proposed by using the local symmetry projection. The recovery method is applied to the Nédélec interpolation to obtain the superconvergence of postprocessed Nédélec interpolation. Combining with the superclose result between the Nédélec interpolation and edge finite element approximation, it is shown that the postprocessed edge finite element solution superconverges to the exact solution. Numerical examples are presented to illustrate our theoretical analysis.