Multiple periodic solutions for a nonlinear first order functional differential equations with applications to population dynamics

摘要

In this work using Legget–Williams multiple fixed point theorem, we have obtained different sufficient conditions for the existence of at least three nonnegative periodic solutions for the first order functional differential equations of the formy′(t)=-a(t)y(t)+λf(t,y(h(t))),using Legget–Williams multiple fixed point theorem.