Index estimates for strongly indefinite functionals, periodic orbits and homoclinic solutions of first order Hamiltonian systems
Tóm tắt
We improve Benci and Rabinowitz's Linking theorem for strongly indefinite functionals, giving estimates for a suitably defined relative Morse index of critical points. Such abstract result is applied to the existence problem of periodic orbits and homoclinic solutions of first order Hamiltonian systems in cases where the Palais-Smale condition does not hold.