Special Math/Physics Seminar

Fivebranes and 4-manifolds

Abhijit Gadde

Institute for Advanced Study

I will talk about a novel invariant of four manifolds. Using the so called fivebrane of M-theory, we associate a two dimensional physical theory to a 4-manifold. From mathematical point of view, this theory can be thought of as a higher categorical data, which can be distilled to get more familiar quantities such as Donaldson-Witten invariants and Euler characteristics of instanton moduli spaces. This construction is useful from physics point of view as well, as the Kirby moves on 4-manifolds get mapped to non-trivial dualities of the 2d theory.