Sufficient conditions for the existence positive periodic solutions of a class of neutral delay models with feedback control

摘要

With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree, easily verifiable criteria are established for the global existence of positive periodic solutions of a neutral model with periodic delays and feedback controldndt=n(t)a(t)−β(t)n(t)−∑i=1nbi(t)n(t−τi(t))−∑i=1nci(t)n′(t−γi(t))−δ(t)u(t)−∑i=1ndi(t)u(t−σi(t)),dudt=−e(t)u(t)+f(t)n(t)+∑i=1ngi(t)n(t−ηi(t)).Our results extend and improve existing results, and have further applications in population dynamics.