QUASI-EQUILIBRIUM PROBLEMS AND FIXED POINT THEOREMS OF SEPARATELY L.S.C AND U.S.C MAPPINGS

Abstract

In this paper, we apply our new results on quasi-variational inequality problems in [5] to generalized quasi-equilibrium problems.Some sufficient conditions on the existence of solutions are shown. In particular, we establish several results on the existence of solutions to fixed points of lower semi-continuous mappings without conditions on the closedness of values. These generalize some well-known fixed point theorems obtained by previous authors as F. E. Browder and Ky Fan, X. Wu, L. J. Lin, and Z. T. Yu etc.