Periodic problem with a potential Landesman Lazer condition.
Periodic solutions for second order Hamiltonian systems
By using the least action principle and minimax methods in critical point theory, some existence theorems for periodic solutions of second order Hamiltonian systems are obtained.
Periodic solutions for second-order Hamiltonian systems with the p-Laplacian.
Pohybové integrály v mechanice vyššího řádu a v teorii polí