Line defects in conformal field theory: from weak to strong coupling

TL;DR

This paper explores conformal line defects in various regimes, employing innovative methods like the analytic bootstrap, with applications spanning quantum field theories and condensed matter systems.

Contribution

It introduces new analytical techniques for studying conformal line defects in both weak and strong coupling regimes, focusing on supersymmetric and magnetic line models.

Findings

Development of analytic bootstrap methods for line defects

Insights into supersymmetric Wilson lines in N=4 SYM

Applications of magnetic lines in 3D condensed matter

Abstract

Conformal field theory finds applications across diverse fields, from statistical systems at criticality to quantum gravity through the AdS/CFT correspondence. These theories are subject to strong constraints, enabling a systematic non-perturbative analysis. Conformal defects provide a controlled means of breaking the symmetry, introducing new physical phenomena while preserving crucial benefits of the underlying conformal symmetry. This thesis investigates conformal line defects in both the weak- and strong-coupling regimes. Two distinct classes of models are studied. First, we focus on the supersymmetric Wilson line in $\mathcal{N}=4$ Super Yang--Mills, which serves as an ideal testing ground for the development of innovative techniques such as the analytic conformal bootstrap. The second class consists of magnetic lines in Yukawa models, which have fascinating applications in $3d$ condensed-matter systems. These systems have the potential to emulate phenomena observed in the Standard Model in a low-energy setting.