4 dec 2025 -- 11:30   [open in google calendar]

Abstract.

In classical KAM theory, a certain nondegeneracy of the integrable Hamiltonian is crucial to show the existence of invariant tori when perturbing. These invariant tori are graphs of Lipschitz functions. However, when such nondegeneracy is violated, very little is known. Inspired by some numerical examples of Simó, we will show the existence of meandering (non-graphic) invariant tori and that they are generic. This is a joint work in progress with Vadim Kaloshin and Illya Koval.