Index estimates for strongly indefinite functionals, periodic orbits and homoclinic solutions of first order Hamiltonian systems
The authors prove an extension of the Benci and Rabinowitz's Linking Theorem for strongly indefinite functionals. Moreover they give an estimate of the relative Morse index of critical points. Such abstract results are applied to the study of the existence of periodic or homoclinic orbits of Hamiltonian systems in cases where the Palais-Smale condition does not hold.
scientific article; zbMATH DE number 1563307