TY - JOUR A1 - Karl, Veronika A1 - Neitzel, Ira A1 - Wachsmuth, Daniel T1 - A Lagrange multiplier method for semilinear elliptic state constrained optimal control problems JF - Computational Optimization and Applications N2 - In this paper we apply an augmented Lagrange method to a class of semilinear ellip-tic optimal control problems with pointwise state constraints. We show strong con-vergence of subsequences of the primal variables to a local solution of the original problem as well as weak convergence of the adjoint states and weak-* convergence of the multipliers associated to the state constraint. Moreover, we show existence of stationary points in arbitrary small neighborhoods of local solutions of the original problem. Additionally, various numerical results are presented. KW - optimal control KW - semilinear elliptic operators KW - state constraints KW - augmented Lagrange method Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232811 SN - 0926-6003 VL - 77 ER - TY - JOUR A1 - Natemeyer, Carolin A1 - Wachsmuth, Daniel T1 - A proximal gradient method for control problems with non-smooth and non-convex control cost JF - Computational Optimization and Applications N2 - We investigate the convergence of the proximal gradient method applied to control problems with non-smooth and non-convex control cost. Here, we focus on control cost functionals that promote sparsity, which includes functionals of L\(^{p}\)-type for p\in [0,1). We prove stationarity properties of weak limit points of the method. These properties are weaker than those provided by Pontryagin’s maximum principle and weaker than L-stationarity. KW - sparse control problems KW - proximal gradient method KW - non-smooth and non-convex optimization Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-269069 SN - 1573-2894 VL - 80 IS - 2 ER -