TY - JOUR T1 - Constructing Order Two Superconvergent WG Finite Elements on Rectangular Meshes AU - Ye , Xiu AU - Zhang , Shangyou JO - Numerical Mathematics: Theory, Methods and Applications VL - 1 SP - 230 EP - 241 PY - 2023 DA - 2023/01 SN - 16 DO - http://doi.org/10.4208/nmtma.OA-2022-0082 UR - https://global-sci.org/intro/article_detail/nmtma/21350.html KW - Finite element, weak Galerkin method, stabilizer free, rectangular mesh. AB -

In this paper, we introduce a stabilizer free weak Galerkin (SFWG) finite element method for second order elliptic problems on rectangular meshes. With a special weak Gradient space, an order two superconvergence for the SFWG finite element solution is obtained, in both $L^2$ and $H^1$ norms. A local post-process lifts such a $P_k$ weak Galerkin solution to an optimal order $P_{k+2}$ solution. The numerical results confirm the theory.