Title: Surface diagrams and 4-manifolds (following Jonathan Williams)
Speaker: Siddhartha Gadgil
Date: 12 February 2013
Time: 11:15 a.m.
Venue: LH-III, Department of Mathematics
I will describe work of Jonathan Williams giving a description of smooth 4-manifolds in terms of certain collections of closed curves on surfaces and certain moves on them. This builds on constructions using Lefschetz pencils and their variants, but is a completely elementary description.