Three periodic solutions for perturbed second order Hamiltonian systems

Abstract: In this paper we study the existence of three distinct solutions for the following problem where , T is a real positive number, is a continuous map from the interval to the set of N-order symmetric matrices. We propose sufficient conditions only on the potential F. More precisely, we assume that G satisfies only a usual growth condition which allows us to use a variational approach. [Copyright &y& Elsevier]