University of Toronto's Symplectic Geometry Seminar

September 12, 2005, 2:10pm
Bahen 6183

Johan Martens

University Toronto

Instanton counting and non-abelian localization

Abstract: Nekrasov has shown how the low-energy behaviour of certain super-symmetric quantum field theories can be derived from calculating equivariant volumes of moduli-spaces of instantons. We review this and related recent work, and then sketch an alternative method in symplectic geometry for calculating the equivariant volumes, using varying compactifications of the ADHM spaces and the Jeffrey-Kirwan method of non-abelian localization. The advantage of this method is that it does not require smoothness of the moduli-spaces, and is therefore very suited for calculations on the moduli-spaces for classical gauge groups other than SU(n).