Abstract and Applied Analysis
Volume 2013 (2013), Article ID 420835, 17 pages
http://dx.doi.org/10.1155/2013/420835
Review Article

Existence for Singular Periodic Problems: A Survey of Recent Results

Jifeng Chu,1 Juntao Sun,2 and Patricia J. Y. Wong3

1Department of Mathematics, College of Science, Hohai University, Nanjing 210098, China
2School of Science, Shandong University of Technology, Zibo, Shandong 255049, China
3School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798

Received 13 December 2012; Accepted 11 January 2013

Academic Editor: Yonghui Xia

Copyright © 2013 Jifeng Chu 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 present a survey on the existence of periodic solutions of singular differential equations. In particular, we pay our attention to singular scalar differential equations, singular damped differential equations, singular impulsive differential equations, and singular differential systems.