- 98-121 Chandre C., Jauslin H.R.
- Twistless Version of Thirring's Approach to the KAM Theorem
for Quadratic Hamiltonians
Mar 4, 98
(auto. generated ps),
of related papers
Abstract. We give a proof of the KAM theorem on the existence of
invariant tori for weakly perturbed Hamiltonian systems,
based on Thirring's approach for Hamiltonians that are
quadratic in the action variables. The main point of this
approach is that the iteration of canonical transformations
on which the proof is based stays within the space of
quadratic Hamiltonians. We show that Thirring's proof for
nondegenerate Hamiltonians can be adapted to twistless
Hamiltonians. This twistless assumption, in fact,
drastically simplifies Thirring's proof.