Holographic S-fold theories at one loop

TL;DR

This paper investigates one-loop corrections in holographic 4d CFTs with S-folds, revealing that anomalous dimensions depend non-rationally on spin, which indicates dynamical differences from simpler theories.

Contribution

It introduces a novel bootstrap approach to compute one-loop anomalous dimensions in S-fold holographic theories without assuming specific special functions.

Findings

Anomalous dimensions are non-rational functions of spin.

The analysis uses Casimir singular and regular terms iteratively.

Differences from previous theories appear at the one-loop level.

Abstract

A common feature of tree-level holography is that a correlator in one theory can serve as a generating function for correlators in another theory with less continuous symmetry. This is the case for a family of 4d CFTs with eight supercharges which have protected operators dual to gluons in the bulk. The most recent additions to this family were defined using S-folds which combine a spatial identification with an action of the S-duality group in type IIB string theory. Differences between these CFTs which have a dynamical origin first become manifest at one loop. To explore this phenomenon at the level of anomalous dimensions, we use the AdS unitarity method to bootstrap a one-loop double discontinuity. Compared to previous studies, the subsequent analysis is performed without any assumption about which special functions are allowed. Instead, the Casimir singular and Casimir regular terms are extracted iteratively in order to move from one Regge trajectory to the next. Our results show that anomalous dimensions in the presence of an S-fold are no longer rational functions of the spin.