E. Casas et F. Troltzsch, Second-order necessary optimality conditions for some state-constrained control problems of semilinear elliptic equations, APPL MATH O, 39(2), 1999, pp. 211-227
In this paper we are concerned with some optimal control problems governed
by semilinear elliptic equations. The case of a boundary control is studied
. We consider pointwise constraints on the control and a finite number of e
quality and inequality constraints on the state. The goal is to derive firs
t- and second-order optimality conditions satisfied by locally optimal solu
tions of the problem.