# Variations on S-fold CFTs

## TL;DR

This paper explores generalized S-fold superconformal field theories with T(G) links, analyzing their moduli spaces and mirror symmetry, including novel G_2 cases without known brane constructions.

## Contribution

It extends previous S-fold CFT studies by incorporating T(G) links for self-dual G, providing new quiver constructions and mirror pairs, especially for G_2.

## Key findings

- Proposes new S-fold quivers with T(G) links for G=SO(2N), USp'(2N), G_2.
- Analyzes moduli spaces and tests dualities via mirror symmetry.
- Introduces novel G_2 quivers without existing brane models.

## Abstract

A local SL(2,Z) transformation on the Type IIB brane configuration gives rise to an interesting class of superconformal field theories, known as the S-fold CFTs. Previously it has been proposed that the corresponding quiver theory has a link involving the T(U(N)) theory. In this paper, we generalise the preceding result by studying quivers that contain a T(G) link, where G is self-dual under S-duality. In particular, the cases of G = SO(2N), USp'(2N) and G_2 are examined in detail. We propose the theories that arise from an appropriate insertion of an S-fold into a brane system, in the presence of an orientifold threeplane or an orientifold fiveplane. By analysing the moduli spaces, we test such a proposal against its S-dual configuration using mirror symmetry. The case of G_2 corresponds to a novel class of quivers, whose brane construction is not available. We present several mirror pairs, containing G_2 gauge groups, that have not been discussed before in the literature.