De Simoi's seminar in Pisa

Monday  20/7/2015, h 11:30-12:30 Sala Conferenze (Puteano, Centro De Giorgi)

Jacopo De Simoi (University of Toronto)

“AN INTEGRABLE BILLIARD CLOSE TO AN ELLIPSE OF SMALL ECCENTRICITY IS AN ELLIPSE”

Abstract: In 1927 G. Birkhoff conjectured that if a billiard in a strictly convex smooth domain is integrable, the domain has to be an ellipse (or a circle). The conjecture is still wide open, and presents remarkable relations with open questions in inverse spectral theory and spectral rigidity. In the talk we show that a version of Birkhoff’s conjecture is true for small perturbations of ellipses of small eccentricity. This is joint work with A. Avila and V. Kaloshin