Date: Wednesday, March 31, 2010
Title: Sumner Myers Colloquium : Counting maps between complex curves
Abstract: GromovWitten invariants "count" holomorphic maps from a Riemann surfaces C to a target space X, where "count" is hiding a large technical headache. Physics predicts many wonderful things about GW invariants which mathematicians find intriguing but very difficult to prove. When X is itself a complex curve, however, there is an easier, classical, combinatorial way to actually count such maps, known as Hurwitz theory, which leads to the verification of physical conjectures. If time permits, we'll discuss how the story changes when certain orbifolds that look like footballs are considered instead.
Speaker: Paul Johnson
Institution: Imperial College
