Dia: Dimecres 10 de desembre de 2025
Lloc: Aula T2 (segon pis), Facultat de Matemàtiques i Informàtica, UB.
A càrrec de: Illya Koval, IST Austria
Títol: Fractal-like meanders appear in KAM theory
Resum: In KAM theory, a certain nondegeneracy of the Hessian of the unperturbed Hamiltonian is crucial to show the existence of invariant tori. These invariant tori have to be the graphs of Lipschitz functions. However, when such a type of nondegeneracy is violated, very little is known. Inspired by the works of Simó, we will show the existence of non-graph meandering invariant tori and that they are generic. We discuss meanders of the first order, second order, and even fractal-like meanders. This is a joint work in progress with Vadim Kaloshin and Yi Pan.
Last updated: Mon Dec 8 11:00:01 2025