HET Journal club: Edoardo Vescovi

Speaker: Edoardo Vescovi

Title: Two non-BPS Wilson loops: quark-antiquark potential in defect CFT and circular loop beyond the wavy approximation

Abstract: I will describe interesting features of two observables measured by non-BPS Wilson loops. 
In the first part I determine the potential energy of a quark-antiquark pair in a Higgsed variant of N=4 SYM with a codimension-1 defect [1708.04884] at weak coupling via gauge perturbation theory and at strong coupling in the dual D3-D5 brane system. In the latter regime, the relevant string free energy displays Gross-Ooguri transitions between a connected string surface and a phase where the string breaks into two disconnected surfaces.
In the second part I consider small deformations of the circular Wilson loop in N=4 SYM and of the dual minimal surface in hyperbolic space H_3. The formalism introduced by Kruczenski showed that the Wilson loop vev at strong coupling is invariant under certain deformations of the boundary contour. This symmetry was later found by Dekel to break down at weak coupling only at an unexpected high order in the deformation parameter. I report ongoing progress to understand this approximate symmetry in gauge theory.