Universality of Algebraic Laws in Hamiltonian Systems

Hamiltonian mixed systems with unbounded phase space are typically characterized by two asymptotic algebraic laws: decay of recurrence time statistics (gamma) and superdiffusion (beta). We conjecture the universal exponents gamma=beta=3/2 for trapping of trajectories to regular islands based on our analytical results for a wide class of area-preserving maps. For Hamiltonian mixed systems with a bounded phase space the interval 3/2 <=gamma(b)<= 3 is obtained, given that trapping takes place. A number of simulations and experiments by other authors give additional support to our claims.