Orateur
Victor Kleptsyn
Description
My talk will follow a joint work with Maximiliano Escayola, devoted
to the study of critical regularities for nilpotent group actions.
The questions of critical regularities have been studied
by many authors in many different contexts: starting from the
classical Denjoy theorem and example, there are works by M. Herman, J.-C. Yoccoz,
N. Kopell, B. Deroin, A. Navas, C. Rivas, E. Jorquera, Kim, T. Koberda, any many others.
We’ll be describing the critical regularity in algebraic terms, introducing some new
technique for establishing the bounds.
