Vectorial form of Ekeland-type variational principle with applications to vector equilibrium problems and fixed point theory

摘要

This paper introduces a vectorial form of equilibrium version of Ekeland-type variational principle. Some equivalent results to our variational principle are given. As applications, we derive the existence of solutions of a vector equilibrium problem in the setting of complete quasi-metric spaces with a W-distance. Caristi-Kirk fixed point theorem for multivalued maps is also established in a more general setting. (c) 2007 Elsevier Inc. All rights reserved.