Lattices, Perfects lattices, Voronoi reduction theory, modular forms, computations of isometries and automorphisms 1
By Gabriele Nebe
High dimensional cohomology of SL_n(Z) and its principal congruence subgroups 3
By Peter Patzt
By Anton Zorich
Appears in collection : Summer School 2018 - Teichmüller dynamics, mapping class groups and applications.
In the first two lectures I will try to tell (or, rather, to give an idea) of how Maryam Mirzakhani has counted simple closed geodesics on hyperbolic surfaces. I plan to briefly mention her count of Weil-Peterson volumes and her proof of Witten's conjecture, but only on the level of some key ideas. In the last lecture I plan to show how ideas of Mirzakhani work in counting problems related to flat surfaces, namely, in computation of Masur-Veech volumes and in counting meanders.