Bootstrapping line defects in $\mathcal{N}=2$ theories

Understand

We study half-BPS line defects in $\mathcal{N}=2$ 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 $\mathfrak{osp}(4^*|2)$ 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.