{ "id": "2103.13535", "version": "v1", "published": "2021-03-25T00:11:08.000Z", "updated": "2021-03-25T00:11:08.000Z", "title": "Convergence of the Birkhoff normal form sometimes implies convergence of a normalizing transformation", "authors": [ "Rafael de la Llave", "Maria Saprykina" ], "categories": [ "math.DS" ], "abstract": "Consider an analytic Hamiltonian system near its analytic invariant torus $\\mathcal T_0$ carrying zero frequency. We assume that the Birkhoff normal form of the Hamiltonian at $\\mathcal T_0$ is convergent and has a particular form: it is an analytic function of its non-degenerate quadratic part. We prove that in this case there is an analytic canonical transformation -- not just a formal power series -- bringing the Hamiltonian into its Birkhoff normal form.", "revisions": [ { "version": "v1", "updated": "2021-03-25T00:11:08.000Z" } ], "analyses": { "keywords": [ "birkhoff normal form", "implies convergence", "normalizing transformation", "analytic hamiltonian system", "analytic invariant torus" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }