A Topological Proof of Birkhoff's Theorem

Dynamical Systems Working Seminar
Friday, October 13, 2017 - 15:00
1 hour (actually 50 minutes)
Skiles 154
GT Math
Birkhoff's Theorem is a result useful in characterizing the boundary of certain open sets U ⊂ T^1 x [0, inf) which are invariant under "vertical-tilting" homeomorphisms H. We present the method used by A. Fathi to prove Birkhoff's theorem, which develops a series of lemmas using topological arguments to prove that this boundary is a graph.