LAGRANGIAN METHODS FOR OPTIMAL CONTROL PROBLEMS GOVERNED BY QUASI-HEMIVARIATIONAL INEQUALITIES.

The aim of this paper is to study an optimal control problem governed by a quasihemivariational inequality by using nonlinear Lagrangian methods. We first show the existence of solutions to the inequality problem, and then, we establish several sufficient conditions for the zero duality gap property between the optimal control problem and its nonlinear dual problem. [ABSTRACT FROM AUTHOR]