© 2002 by London Mathematical Society
© The London Mathematical Society
Periodic Solutions of Neutral Functional Differential Equations
Department of Applied Mathematics, Hunan University Changsha, Hunan, China 410082
Department of Applied Mathematics, Hunan University Changsha, Hunan, China 410082, zcwang{at}mail.hunu.edu.cn
Department of Mathematics and Statistics, Memorial University of Newfoundland St John's, NF, Canada A1C 5S7, xzou{at}math.mun.ca
Received 12 September 2000. Revision received 8 June 2001.
Periodic neutral functional differential equations are considered. Sufficient conditions for existence, uniqueness and global attractivity of periodic solutions are established by combining the theory of monotone semiflows generated by neutral functional differential equations and Krasnosel'skii's fixed-point theorem. These results are applied to a concrete neutral functional differential equation that can model single-species growth, the spread of epidemics, and the dynamics of capital stocks in a periodic environment.