Existence of periodic solutions for non-autonomous second-order Hamiltonian systems

Abstract

The purpose of this paper is to study the existence of periodic solutions for a class of non-autonomous second order Hamiltonian systems. New results are obtained by using the least action principle and the minimax methods, without the so-called Ahmad-Lazer-Paul type condition.

Keywords

• Periodic solution
• Hamiltonian systems
• critical point
• variational method