A priori error estimates for higher order variational discretization and mixed finite element methods of optimal control problems

* Correspondence: zulianglux@126. com College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan 411105, PR China Full list of author information is available at the end of the article Abstract In this article, we investigate a priori error estimates for the optimal control problems governed by elliptic equations using higher order variational discretization and mixed finite element methods. The state and the co-state are approximated by the order k Raviart-Thomas mixed finite element spaces and the control is not discreted. A priori error estimates for the higher order variational discretization and mixed finite element approximation of control problems are obtained. Finally, we present some numerical examples which confirm our theoretical results. Mathematics Subject Classification 1991: 49J20; 65N30.