One-form symmetries in $\mathcal{N} = 3$ $S$-folds
Antonio Amariti, Davide Morgante, Antoine Pasternak, Simone Rota, Valdo Tatitscheff
TL;DR
This work addresses the problem of identifying global one-form symmetries in non-Lagrangian $\mathcal{N}=3$ SCFTs realized via $S$-fold projections of D3-branes. The authors adapt the IR-based DelZotto method to the Type IIB brane setup by extracting the electromagnetic charges of $(p,q)$-strings, forming a charge lattice, and then quotienting by screening to obtain genuine line operators; maximal mutually local sublattices fix the possible global structures. They provide a complete classification for various $S$-folds, finding a $\mathbb{Z}_3$ one-form symmetry for $S_{3,1}$ and a $\mathbb{Z}_2$ one for $S_{4,1}$ in rank-2 cases, while many other theories exhibit trivial one-form symmetry. The results reproduce known $\mathcal{N}=4$ enhancements and illuminate the potential for non-invertible duality defects, establishing a bridge between brane constructions, lattice of lines, and generalized global symmetries in $\mathcal{N}=3$ theories. This lattice-driven approach enables systematic analysis across ranks and discrete torsion choices and paves the way for exploring non-invertible structures in broader classes of $S$-fold and exceptional $\mathcal{N}=3$ theories.
Abstract
We classify the global one-form symmetries for non-Lagrangian $\mathcal{N}=3$ SCFTs that arise by the action of $S$-fold projections on D3-branes. Such a classification is dictated, on a generic point of the Coulomb branch, by probing the charge spectrum of $(p, q)$-strings in the brane setup. The charge lattice of lines is then obtained by finding the ones that are genuine modulo screening by dynamical particles. The one-form symmetries are then extracted from the maximal sub-lattices of mutually local lines. We further comment on the existence of non-invertible symmetries for some of these $\mathcal{N}=3$ SCFTs.
