TY - JOUR T1 - Superconvergence of a Galerkin FEM for Higher-Order Elements in Convection-Diffusion Problems JO - Numerical Mathematics: Theory, Methods and Applications VL - 3 SP - 356 EP - 373 PY - 2014 DA - 2014/07 SN - 7 DO - http://doi.org/10.4208/nmtma.2014.1320nm UR - https://global-sci.org/intro/article_detail/nmtma/5879.html KW - Singular perturbation, layer-adapted meshes, superconvergence, postprocessing AB -

In this paper we present a first supercloseness analysis for higher-order Galerkin FEM applied to a singularly perturbed convection-diffusion problem. Using a solution decomposition and a special representation of our finite element space, we are able to prove a supercloseness property of $p + 1/4$ in the energy norm where the polynomial order $p ≥ 3$ is odd.