Speaker
Alejandro Cabo-Bizet
(King's College)
Description
I will explain how in the expansion near roots of unity, the four-dimensional superconformal index decomposes into a sum over independent sectors, some of them described by A-models wrapping Riemann surfaces. Starting from the four dimensional index the partition function of these lower dimensional systems is reduced to a sum over vacua of the specific A-model. The number of degrees of freedom is subleading in the large N expansion, and their contribution to the index, which seems to naturally organize as a sum over genus-g contributions, calls for a string dual interpretation.
