Meyer, Christian2021-12-172021-12-172005-04-142197-8085https://depositonce.tu-berlin.de/handle/11303/15566http://dx.doi.org/10.14279/depositonce-14339We consider a control constrained optimal control problem governed by a semilinear elliptic equation with nonlocal interface conditions. These conditions occur during the modeling of diffuse-gray conductive-radiative heat transfer. After stating first-order necessary conditions, second-order sufficient conditions are derived that account for strongly active sets. These conditions ensure local optimality in a $L^s$-neighborhood whereby the underlying analysis allows to use weaker norms than $L^\infty$.en510 Mathematikoptimal controlsemilinear elliptic equationsnonlocal interface conditionssecond-order sufficient optimality conditionsResearch Paper