Optimization Tools for Solving Equilibrium Problems with Nonsmooth Data

The paper deals with the gap function approach for equilibrium problems with locally Lipschitz data. The gap function inherits the locally Lipschitz continuity of the data. Hence, the connections between its generalized directional derivatives, monotonicity conditions on the equilibrium bifunction and descent properties, can be analyzed. In turn, this analysis leads to devise two descent methods. Finally, the results of preliminary numerical tests are reported.