• Viviane Baladi. The spectrum of Sinai billiard flows (Joint work with M. Demers and C. Liverani) Sinai billiard maps in dimension two have been proved to be exponentially mixing by L.-S. Young twenty years ago. Recent work of Demers and Zhang gives a spectral gap for their natural transfer operators on a suitable anisotropic Banach space. Understanding Sinai billiard flows is more difficult. ...