一类种群动力学模型正概周期解的存在性

Existence of Positive Almost Periodic Solution for a Class of Population Differential Equation with Infinite Delay

本文讨论了一类时滞微分方程正概周期解的存在性问题,利用锥中u_0-凹算子与增算子的性质,不仅得到了上述系统的正概周期解的存在性与非存在性的结论,还改进了现有的结果,并且我们的方法也适用于更一般的系统．

In this paper, a class of population differential equation with infinite delay as follows N＇（t）=-γ（t）N（t）＋α（t）∫0^∞k（s）N（t-s）e^-β（t）N（t-s）ds,t≥0 is disscussed. Sufficient conditions for the existence of positive almost periodic solutions are obtained by using u0-concave operator and increasing operator. Our results are new and some existing statements are improved.