Coordinates: JH Michell Theatre in the Richard Berry Building
Speaker: Ian Agol (UC Berkeley)
Title: Presentation length and Simon's conjecture
Abstract: (Joint work with Yi Liu.)

In this paper, we show that any knot group maps onto at most finitely many knot groups. This gives an affirmative answer to a conjecture of J. Simon. We also bound the diameter of a closed hyperbolic 3-manifold linearly in terms of the presentation length of its fundamental group, improving a result of White.