Superconvergence Properties Of Optimal Control Problems For Elliptic Equation

An optimal control problem for a 2-d elliptic equation is investigatedwith pointwise control constrains. This paper is concerned with discretiza-tion of the control by piecewise constant functions , the state and the adjointstate are discretized by finite elements, we constructed new vI ,and it isproved that these approximations have convergence order h~2. Moreover,approximations of optimal solutions ???will be constructed by projection ofthe discrete adjoint state, and the approximations have convergence orderh~2.