Physics Group Meeting

I will describe a proposal for computing the Schur limit of the superconformal index of four-dimensional N = 2 field theories, which counts local operators in the UV, from the spectrum of BPS particles on the Coulomb branch. This proposal can be checked in various Lagrangian examples and has been applied to non-Lagrangian theories such as the Argyres-Douglas theories. The answers match expectations from the connection of Schur operators with two-dimensional chiral algebras. If time permits, I will discuss a generalization to include line defects, and their connection to the other primaries of the associated two-dimensional chiral algebra.