Mathematical Problems in Engineering
Volume 2010 (2010), Article ID 458918, 15 pages
doi:10.1155/2010/458918
Research Article

A Note on Periodic Solutions of Second Order Nonautonomous Singular Coupled Systems

Zhongwei Cao,1,2 Chengjun Yuan,1,3 Daqing Jiang,1 and Xiaowei Wang4

1School of Mathematics and Statistics, Northeast Normal University, Changchun 130024, China
2Department of Applied Mathematics, Changchun Taxation College, Changchun 130117, China
3Department of Mathematics, Harbin University, Harbin 150086, China
4School of Mathematical Sciences, Fudan University, Shanghai 200437, China

Received 25 March 2010; Accepted 25 August 2010

Academic Editor: Alexander P. Seyranian

Copyright © 2010 Zhongwei Cao et al. 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.

Abstract

We establish the existence of periodic solutions of the second order nonautonomous singular coupled systems x′′+a1(t)x=f1(t,y(t))+e1(t) for a.e. t∈[0,T], y′′+a2(t)y=f2(t,x(t))+e2(t) for a.e. t∈[0,T]. The proof relies on Schauder's fixed point theorem.