Rational invariant tori, phase space tunneling, and spectra for non-selfadjoint operators in dimension 2

Abstract

We Study spectral asymptotics and resolvent bounds for non-selfadjoint perturbations of selfadjoint h-pseudodifferential operators in dimension 2, assuming that the classical flow of the unperturbed part is completely integrable. Spectral contributions coming from rational invariant Lagrangian tori are analyzed. Estimating the tunnel effect between strongly irrational (Diophantine) and rational tori, we obtain an accurate description of the spectrum in a suitable complex window, provided that the strength of the non-selfadjoint perturbation » h (or sometimes » h2) is not too large. © 2008 Société Mathématique de France. Tous droits réservés.