Hammerstein integral inclusions in reflexive Banach spaces

In this paper we examine multivalued Hammerstein integral equations defined in a separable reflexive Banach space. We prove existence theorems for bot h the "convex" problem (the multifunction is convex-valued) and the "noncon vex" problem (the multifunction is not necessarily convex-valued). We also show that the solution set of the latter is dense in the solution set of th e former (relaxation theorem). Finally we present some examples illustratin g the applicability of our abstract results.