paper

Regular deformations of completely integrable systems

arXiv:math/0504379

Abstract

We study several aspects of the regular deformations of completely integrable systems. Namely, we prove the existence of a Hamiltonian normal form for these deformations and we show the necessary and sufficient conditions a perturbation has to satisfy in order for the perturbed Hamiltonian to be a first order deformation.

minor typo errors fixed, bibliography updated