TY - JOUR T1 - Error Estimates and Superconvergence of Mixed Finite Element Methods for Optimal Control Problems with Low Regularity AU - Chen , Yanping AU - Hou , Tianliang AU - Zheng , Weishan JO - Advances in Applied Mathematics and Mechanics VL - 6 SP - 751 EP - 768 PY - 2012 DA - 2012/12 SN - 4 DO - http://doi.org/10.4208/aamm.12-12S05 UR - https://global-sci.org/intro/article_detail/aamm/147.html KW - Elliptic equations, optimal control problems, superconvergence, error estimates, mixed finite element methods. AB -

In this paper, we investigate the error estimates and superconvergence property of mixed finite element methods for elliptic optimal control problems. The state and co-state are approximated by the lowest order Raviart-Thomas mixed finite element spaces and the control variable is approximated by piecewise constant functions. We derive $L^2$ and $L^\infty$-error estimates for the control variable. Moreover, using a recovery operator, we also derive some superconvergence results for the control variable. Finally, a numerical example is given to demonstrate the theoretical results.