Original Article
Kyungpook Mathematical Journal 2004; 44(2): 277-291
Published online June 23, 2004
Copyright © Kyungpook Mathematical Journal.
Periodic Solutions in $n$-species Ratio-dependent Food Chain Model with Time Delays
Qiming Liu , Rui Xu
Department of Mathematics, Shijiazhuang Mechanical Engineering College, Shijiazhuang 050003, Hebei, P. R. China
A delayed periodic $n$-species ratio-dependent food chain model is investigated. By using Gaines and Mawhin's continuation theorem of coincidence degree theory, a set of easily verifiable sufficient conditions are derived for the existence of positive periodic solutions to the model.
Keywords: ratio-dependence, time delay, coincidence degree, periodic solution