Fixed Point Theory and Applications
Volume 2011 (2011), Article ID 563136, 8 pages
Research Article

On Fixed Point Theorems of Mixed Monotone Operators

School of Mathematics Sciences, Qufu Normal University, Qufu, Shandong 273165, China

Received 11 November 2010; Accepted 4 January 2011

Academic Editor: T. Benavides

Copyright © 2011 Xinsheng Du and Zengqin Zhao. 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.


We obtain some new existence and uniqueness theorems of positive fixed point of mixed monotone operators in Banach spaces partially ordered by a cone. Some results are new even for increasing or decreasing operators.