Meyer, ChristianPruefert, UweTröltzsch, Fredi2021-12-172021-12-172005-02-182197-8085https://depositonce.tu-berlin.de/handle/11303/15573http://dx.doi.org/10.14279/depositonce-14346A linear-quadratic elliptic control problem with pointwise box constraints on the state is considered. The state-constraints are treated by a Lavrentiev type regularization. It is known that the Lagrange multipliers associated with the regularized state-constraints are functions in L^2. Moreover, the convergence of the optimal control of the regularized problem is proven for regularization parameter tending to zero. To solve the problem numerically, an interior point method and a primal-dual active set strategy are implemented and tested in function space.en510 Mathematiklinear elliptic equationsquadratic optimal control problempointwise state constraintsinterior point methodactive set strategyResearch Paper