关于传染病模型中的非线性积分方程的非负周期解

Positive Periodic Solutions of Nonlinear Integral Eguation for Epidemic Model

在本文中,我们用计算不动点指数的方法来研究发生在传染病流行模型中的一个非线性积分方程x(t)=integral from t-τ(t) to t f(s,x(s))ds的正周期解,文中所提供的方法,除了能更简便地得到最近文献[1],[2],[3]中的大部分存在性结果外,还得到了许多上述文献中没有的存在性和多解结果,其中特别得到了一个三解定理。

In this paper, first we give a some of computatinal formulas of fixed point index, and then we consider the positive periodic solution of a nonlinear integral eguation, which arise in the theory of epidemic model. We obtain many results of eristence and mulitisolutions for this eguation, in particular a threesolution theoren, except for results of in recent years.