A minimax theorem for functions with possibly nonconnected intersections of sublevel sets

摘要

We apply the selection theorem for multivalued mappings with paraconvex values (rather than various versions of KKM-principle) to prove several minimax theorems. In contrast with well-known minimax theorems for coordinatewise semicontinuous functions, in our theorems finite intersections of sublevel or uplevel sets can be nonempty and nonconnected. (c) 2005 Elsevier Inc. All rights reserved.