Fixed Point Theory and Applications
Volume 2007 (2007), Article ID 73246, 9 pages
Research Article

Nonlinear Mean Ergodic Theorems for Semigroups in Hilbert Spaces

Seyit Temir and Ozlem Gul

Department of Mathematics, Arts and Science Faculty, Harran University, Sanliurfa 63200, Turkey

Received 26 December 2006; Accepted 4 April 2007

Academic Editor: Nan-Jing Huang

Copyright © 2007 Seyit Temir and Ozlem Gul. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Let K be a nonempty subset (not necessarily closed and convex) of a Hilbert space and let Γ={T(t);t0} be a semigroup on K and let α(.):[0,)K be an almost orbit of Γ. In this paper, we prove that every almost orbit of Γ is almost weakly and strongly convergent to its asymptotic center.