MS Seminar (Mathematics - String Theory)

Speaker: Sourav Ballav (The Institute of Mathematical Sciences)
Title: Surface operators in N=2 SQCD and Seiberg duality
Date: Tue, Feb 04, 2020, 13:15 - 14:30
Place: Seminar Room A
Related File: 2460.pdf
Abstract: Surface operators in gauge theories are non-local operators supported on co- dimension two submanifold of spacetime. In this talk, I will discuss about half- BPS surface operators in N=2 SQCD in four dimensions with SU(N) gauge group and 2N fundamental flavours following two different approaches. In the first approach, we treat surface operators as monodromy defects and compute the instanton partition function in the presence of such a defect using localization methods. In the second approach we study surface operators as flavour defects: these are coupled 2d/4d quivers with four dimensional SU(N) gauge group as flavour symmetry. The contours specified by a particular Jeffrey- Kirwan residue prescription in the localization analysis map to particular realizations of the surface operator as flavour defects. Seiberg duality of the 2d/4d quivers is mapped to contour deformations of the localization integral which in this case involves a residue at infinity. This is reflected as a modified Seiberg duality rule that shifts the Lagrangian of the purported dual theory by non-perturbative terms.