Journal of Applied Mathematics and Stochastic Analysis 
Volume 12 (1999), Issue 2, Pages 169-178
doi:10.1155/S1048953399000179

A note on multivalued differential equations on proximate retracts

Donal O'Regan

National University of Ireland, Department of Mathematics, Galway, Ireland

Received 1 October 1997; Revised 1 July 1998

Abstract

This paper discusses viable solutions for differential inclusions in Banach spaces. Existence will be established in two steps. In step 1, a nonlinear alternative of Leray-Schauder type [8] for maps with closed graphs will be used to establish a variety of existence principles for the Cauchy differential inclusion. Step 2 involves using the results in step 1 together with some tricks involving the Bouligand cone (and sometimes the Urysohn function) so that new existence criteria can be established for multivalued differential equations on proximate retracts.