Duality and enhancement of symmetry in 5d gauge theories
Gabi Zafrir
TL;DR
This paper investigates dualities and symmetry enhancements in 5d $\mathcal{N}=1$ gauge theories using brane-web constructions and exact 5d superconformal index calculations. The authors show that instanton sectors drive nonperturbative symmetry enhancements (including to exceptional groups like $G_2$) and provide detailed index matches across multiple dual pairs, including quivers with additional $SU(3)$ nodes. By computing perturbative plus instanton contributions and carefully removing decoupled states, they demonstrate a rich network of dualities with consistent quantum global symmetries. The work advances understanding of UV fixed points in 5d theories and suggests broad generalizations to higher-node quivers and potential holographic connections.
Abstract
We study various cases of dualities between $\cal{N}$$=1$ 5d supersymmetric gauge theories. We motivate the dualities using brane webs, and provide evidence for them by comparing the superconformal index. In many cases we find that the classical global symmetry is enhanced by instantons to a larger group including one where the enhancement is to the exceptional group $G_2$.
