Penner's conjecture

Geometry Topology Student Seminar
Wednesday, September 21, 2016 - 14:05
1 hour (actually 50 minutes)
Skiles 006
Georgia Tech
In 1988, Penner conjectured that all pseudo-Anosov mapping classes arise up to finite power from a construction named after him. This conjecture was known to be true on some simple surfaces, including the torus, but has otherwise remained open. I will sketch the proof (joint work with Hyunshik Shin) that the conjecture is false for most surfaces.