Periodic solution of a nonautonomous diffusive food chain system of three species with time delays
A 2-patch food-chain system is studied. In patch I there are three species \(X1\), \(X2\), \(X3\) where \(X2\) predates on \(X1\) and \(X3\) predates on \(X2\). \(X1\) can diffuse between the two patches while \(X2\), \(X3\) cannot. The system has both periodic coefficients and delay. Conditions for the existence of a positive periodic solution are derived by using the continuation theorem of coincidence degree theory.
the continuation theorem of coincidence degree
scientific article; zbMATH DE number 2101834