Abstract and Applied Analysis
Volume 2006 (2006), Article ID 10252, 9 pages
Multiple periodic solutions for a class of second-order
nonlinear neutral delay equations
1Department of Mathematics, Hunan University, Changsha 410082, China
2Department of Mathematics, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, China
Received 14 October 2004; Accepted 12 December 2004
Copyright © 2006 Xiao-Bao Shu and Yuan-Tong Xu. 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.
By means of a variational structure and -group index theory,
we obtain multiple periodic solutions to a class of second-order
nonlinear neutral delay equations of the form.