TY - JOUR T1 - Superconvergence of Finite Element Methods for Optimal Control Problems Governed by Parabolic Equations with Time-Dependent Coefficients JO - East Asian Journal on Applied Mathematics VL - 3 SP - 209 EP - 227 PY - 2018 DA - 2018/02 SN - 3 DO - http://doi.org/10.4208/eajam.030713.100813a UR - https://global-sci.org/intro/article_detail/eajam/10919.html KW - Superconvergence, finite element methods, optimal control problems, parabolic equations, interpolation operator. AB -

In this article, a fully discrete finite element approximation is investigated for constrained parabolic optimal control problems with time-dependent coefficients. The spatial discretisation invokes finite elements, and the time discretisation a nonstandard backward Euler method. On introducing some appropriate intermediate variables and noting properties of the $L^2$ projection and the elliptic projection, we derive the superconvergence for the control, the state and the adjoint state. Finally, we discuss some numerical experiments that illustrate our theoretical results.