Delshams, Amadeu2019-05-072019-05-0719800214-1493https://hdl.handle.net/2445/132772KAM theorem doesn't ensure stability for dynamical systems close to integrable Hamiltonian systems when the dimension of the phase space is more than four . In this case, irregular unstable orbits may occur, arbitrarily close to stable invariant tori . This is the Arnold diffusion . We study here some suf£icient conditions which guarantee the existence of this diffusion .4 p.application/pdfspa(c) Universitat Autònoma de Barcelona, 1980Sistemes hamiltoniansHamiltonian systemsinfo:eu-repo/semantics/article0064362019-05-07info:eu-repo/semantics/openAccess