Taming Mass Gap with Anti-de-Sitter Space

TL;DR

This paper explores how Anti-de-Sitter space influences the mass gap in two-dimensional theories, revealing a boundary-driven transition from gapless to gapped phases, with implications for confinement in gauge theories.

Contribution

It demonstrates a boundary RG flow mechanism induced by a singlet marginal operator that causes a phase transition in AdS-interpolated theories.

Findings

Boundary RG flow leads to a gapped phase from a gapless one.

A singlet marginal operator destabilizes the small-size phase.

Proposes a similar confinement mechanism in gauge theories.

Abstract

Anti-de-Sitter space acts as an infra-red cut off for asymptotically free theories, allowing interpolation between a weakly-coupled small-sized regime and a strongly-coupled flat-space regime. We scrutinize the interpolation for theories in two dimensions from the perspective of boundary conformal theories. We show that the appearance of a singlet marginal operator destabilizes a gapless phase existing at a small size, triggering a boundary renormalization group flow to a gapped phase that smoothly connects to flat space. We conjecture a similar mechanism for confinement in gauge theories.