Periodic Solutions for Some Forced Singular Hamiltonian Systems

Abstract

Several recent papers have studied the existence of periodic solutions of Hamiltonian systems under the influence of a singular potential. The existence of periodic solutions of Hamiltonian systems (HS) is considered to be under the influence of a singular potential. This chapter discusses the methods that can be used to obtain subharmonic solutions of HS. It also presents both the geometrical and less geometrical approaches to HS. The intersection theorems are important tools for obtaining the existence and multiplicity of critical points of functionals using minimax arguments.