TY - JOUR T1 - Achieving Superconvergence by One-Dimensional Discontinuous Finite Elements: The CDG Method AU - Ye , Xiu AU - Zhang , Shangyou JO - East Asian Journal on Applied Mathematics VL - 4 SP - 781 EP - 790 PY - 2022 DA - 2022/08 SN - 12 DO - http://doi.org/10.4208/eajam.121021.200122 UR - https://global-sci.org/intro/article_detail/eajam/20884.html KW - Finite element, conforming DG method, stabilizer free, super-convergent. AB -

Novelty of this work is the development of a finite element method using discontinuous $P_k$ element, which has two-order higher convergence rate than the optimal order. The method is used to solve a one-dimensional second order elliptic problem. A totally new approach is developed for error analysis. Superconvergence of order two for the CDG finite element solution is obtained. The $P_k$ solution is lifted to an optimal order $P_{k+2}$ solution elementwise. The numerical results confirm the theory.