# Meeting Details

Title: Minimal average action and distances in the group of Hamiltonian diffeomorphisms Center for Dynamics and Geometry Seminars Alfonso Sorrentino, Cambridge In this talk I shall discuss a conjecture by K. F. Siburg, relating Mather's minimal average action (or \beta-function) to the asymptotic Hofer's distance in the group of Hamiltonian diffeomorphisms. I shall construct examples of smooth fibrewise convex Hamiltonians for which the asymptotic Hofer distance from the identity gives a strict upper bound to the value at 0 of Mather’s \beta-function, thus providing a negative answer to the conjecture. However, the conjecture becomes true if one considers a different distance (the so-called Viterbo's distance). This is a joint work with Claude Viterbo.

### Room Reservation Information

Room Number: MB106 10 / 27 / 2010 03:35pm - 05:05pm