Characterizations of evenly convex sets and evenly quasiconvex functions

The aim of this paper is to present a geometric characterization of even convexity in separable Banach spaces, which is not expressed in terms of dual functionals or separation theorems. As an application, an analytic equivalent definition for the class of evenly quasiconvex functions is derived.  2002 Elsevier Science (USA). All rights reserved.