Fixed point theorems for multivalued nonexpansive mappings satisfying inwardness conditions

Abstract

Let X be a Banach space whose characteristic of noncompact convexity is less than 1 and satisfies the non-strict Opial condition. Let C be a bounded closed convex subset of X, KC(X) the family of all compact convex subsets of X and T a nonexpansive mapping from C into KC(X) with bounded range. We prove that T has a fixed point. The non-strict Opial condition can be removed if, in addition, T is an 1-χ-contractive mapping.