Flavor Symmetry of 5d SCFTs, Part 2: Applications

TL;DR

<3-5 sentence high-level summary>This work addresses determining when a 5d SCFT, constructed by integrating out BPS states from a 6d SCFT on a circle, exhibits enhanced flavor symmetry at its UV fixed point, focusing on theories that mass-deform to 5d $\mathcal{N}=1$ gauge theories with simple algebras. The authors apply a geometric, M-theory-based method relying on the extended Coulomb branch and $\mathbb{P}^1$-fibered non-compact surfaces to encode flavor symmetries, tracing RG flows via flop transitions and surface decoupling. They provide a comprehensive, rank-stratified catalog of enhanced flavor symmetries for 5d SCFTs corresponding to simple gauge algebras up to rank 7, and supply detailed derivations in a dedicated section that corroborate existing literature and dual gauge descriptions. The results sharpen the understanding of flavor-symmetry enhancement mechanisms and supply a robust geometric framework for exploring UV completions and dualities in five dimensions.

Abstract

In Part 1 of this series of papers, we described a general method for determining the flavor symmetry of any 5d SCFT which can be constructed by integrating out BPS particles from some 6d SCFT compactified on a circle. In this part, we apply the method to explicitly determine the flavor symmetry of those 5d SCFTs which reduce, upon a mass deformation, to some 5d N=1 gauge theory carrying a simple gauge algebra. In these cases, the flavor symmetry of the 5d gauge theory is often enhanced at the conformal point. We use our method to determine this enhancement.