Invariant tori in Hamiltonian systems with two degrees of freedom in a neighborhood of a resonance
The paper deals with a question on invariant tori in Hamiltonian systems with two degrees of freedom in a neighborhood of a resonance. First an upper estimate is obtained for the difference of the frequencies on two invariant curves, bounding a resonance zone of an area-preserving close to integrable map. Analogous results for such Hamiltonian systems are presented. The authors also state the conjecture, that generically the lower estimate is of the same order.
scientific article; zbMATH DE number 1340945