Fixed Point Theory and Applications 
Volume 2006 (2006), Article ID 82080, 13 pages
doi:10.1155/FPTA/2006/82080

Nonexpansive mappings defined on unbounded domains

A. Kaewcharoen1 and W. A. Kirk2

 1Department of Mathematics, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand
2Department of Mathematics, The University of Iowa, Iowa City 52242-1419, IA, USA
Received 18 January 2006; Accepted 23 January 2006

Abstract

We obtain fixed point theorems for nonexpansive mappings defined on unbounded sets. Our assumptions are weaker than the asymptotically contractive condition recently introduced by Jean-Paul Penot.