String Journal Club: Aleix Gimenez-Grau
Speaker: Aleix Gimenez-Grau
Title: Bootstrapping line defects in N=2 theories
Abstract: We study half-BPS line defects in N=2 superconformal theories using the bootstrap approach. We concentrate on local excitations constrained to the defect, which means the system is a 1d defect CFT with osp(4*|2) symmetry. In order to study correlation functions, we construct a suitable superspace and then use the Casimir approach to calculate a collection of new superconformal blocks. Special emphasis is given to the displacement operator, which controls deformations orthogonal to the defect and is always present in a defect CFT. After writing crossing symmetry we proceed with a numerical and analytical bootstrap analysis. We obtain numerical bounds on the CFT data and compare them to known solutions. We also present an analytic perturbative solution to the crossing equations, and argue that this solution captures line defects in N=2 gauge theories at strong coupling.