On Nonconvex Pseudomonotone Equilibrium Problems with Applications

In this paper, we provide a further study for nonconvex pseudomonotone equilibrium problems and nonconvex mixed variational inequalities by using global directional derivatives. We provide finer necessary and sufficient optimality conditions for both problems in the pseudomonotone case and, as a consequence, a characterization for a point to be a solution for nonconvex equilibrium problems is given. Finally, we apply the golden ratio algorithm for a class of nonconvex functions in equilibrium problems and mixed variational inequalities.