A KAM theorem for the defocusing NLS equation

作者:Kappeler Thomas*; Liang Zhenguo
来源:Journal of Differential Equations, 2012, 252(6): 4068-4113.
DOI:10.1016/j.jde.2011.11.028

摘要

In this paper we prove a KAM theorem for the defocusing NLS equation in one space dimension with periodic boundary conditions. The novelty of our result is that it is valid not only near the zero solution, but on the entire Sobolev space H-N(T,C) with N is an element of Z(>= 1). In particular, the invariant tori which persist under small Hamiltonian perturbations might be far away from the zero potential.

全文