Discrete Dynamics in Nature and Society
Volume 2009 (2009), Article ID 239209, 18 pages
doi:10.1155/2009/239209
Multiple positive periodic solutions for delay differential system
Zhao-Cai Hao1
, Ti-Jun Xiao2
and Jin Liang2
1Department of Mathematics, Qufu Normal University, Qufu, Shandong 273165, China
2Department of Mathematics, University of Science and Technology of China, Hefei 230026, China
Abstract
We obtain some existence results for multiple positive periodic solutions of some delay differential systems. Examples are presented as applications. For a general positive integer m≥2, main results of this paper do not appear in former literatures as we know. Comparing with the existing results, our results are new also when m=1.