Orateur
Description
Nekhoroshev theorem in its original form ensures stability over exponentially long times of perturbations of integrable Hamiltonian systems under a generic nondegeneracy condition introduced by Nekhoroshev and called Steepness.
Here we consider the case of a perturbation which depends quasiperiodically on time and prove that if the frequencies of the forcing are Diophantine and the unperturbed integrable system fulfills a generic nondegeneracy condition generalizing steepness, then the actions are stable over exponentially long times.
Previous results only dealt with perturbations of convex integrable systems. The proof is based on a generalization of the technique by Nekhoroshev as improved by Guzzo Chierchia Benettin and on some new ideas.
Joint work with Santiago Barbieri, Mar Giralt and Beatrice Langella.
