A Note on Periodic Solutions of Second Order Nonautonomous Singular Coupled Systems

摘要

We establish the existence of periodic solutionsof the second order nonautonomous singular coupled systems x′′+a1(t)x=f1(t,y(t))+e1(t) for a.e. t∈[0,T], y′′+a2(t)y=f2(t,x(t))+e2(t) for a.e. t∈[0,T]. The proof relies on Schauder's fixed point theorem.