Graduate Student / Postdoc Seminar

Quantifying simple connectivity: an introduction to the Dehn function

Speaker: Robert Young, Courant

Location: Warren Weaver Hall 1302

Date: Friday, October 27, 2017, 1 p.m.


Many theorems start by taking an existence theorem and asking "How many?" or "How big?" or "How fast". The best-known example may be the prime number theorem. Euclid proved that infinitely many primes exist, and the prime number theorem describes how quickly they grow. I'll discuss what happens when you apply the same idea to simple connectivity. In a simply-connected space, any closed curve is the boundary of some disc, but how big is that disc? And what can that tell you about the geometry of the space?


Pizza and drinks at 12:45 p.m.