Lecture 1: Baby model: rotation of a circle; Euclidean algorithm as a
renormalisation procedure; moduli space of flat tori; geodesic flow on the
modular curve. True story: interval exchange transformations; Rauzy induction
as a renormalisation procedure; moduli space of Abelian differentials;
Teichmüller geodesic flow. Lecture 2: Counting closed geodesics on flat surfaces; Siegel-Veech
constants; principal boundary of the moduli spaces of Abelian differentials.
