A wandering domain for a diffeomorphism $\Psi $ of $\mathbb A^n=T^*\mathbb T^n$ is an open connected set $W$ such that $\Psi ^k(W)\cap W=\emptyset $ for all $k\in \mathbb Z^*$. The authors endow $\mathbb A^n$ with its usual exact symplectic structure. An integrable diffeomorphism, i.e., the time-one map $\Phi ^h$ of a Hamiltonian $h: \mathbb A^n\to \mathbb R$ which depends only on the action variables, has no nonempty wandering domains.
The aim of this paper is to estimate the size (measure and Gromov capacity) of wandering domains in the case of an exact symplectic perturbation of $\Phi ^h$, in the analytic or Gevrey category. Upper estimates are related to Nekhoroshev theory; lower estimates are related to examples of Arnold diffusion. This is a contribution to the ``quantitative Hamiltonian perturbation theory'' initiated in previous works on the optimality of long term stability estimates and diffusion times; the emphasis here is on discrete systems because this is the natural setting to study wandering domains.
Introduction
Presentation of the results
Stability theory for Gevrey near-integrable maps
A quantitative KAM result--proof of Part (i) of Theorem D
Coupling devices, multi-dimensional periodic domains, wandering domains
Appendices
Appendix A. Algebraic operations in $\mathscr O_k$
Appendix B. Estimates on Gevrey maps
Appendix C. Generating functions for exact symplectic $C^\infty $ maps
Appendix D. Proof of Lemma 2.5
Bibliography.
Laurent Lazzarini, Universite Paris VI, France.
Jean-Pierre Marco, Universite Paris VI, France.
David Sauzin, Observatoire de Paris, France.
