Subharmonic solutions of planar Hamiltonian systems via the Poincaré́-Birkhoff theorem

  • Alberto Boscaggin
Keywords: Subharmonic solutions, Poincaré-Birkhoff fixed point theorem, Rotation number


We revisit some recent results obtained in [1] about the existence of subharmonic solutions for a class of (nonautonomous) planar Hamiltonian systems, and we compare them with the existing literature. New applications to undamped second order equations are discussed, as well.