Discrete quotients of 3-dimensional $$ \mathcal{N}=4 $$ Coulomb branches via the cycle index

Abstract

Abstract The study of Coulomb branches of 3-dimensional $$ \mathcal{N}=4 $$ N = 4 gauge theories via the associated Hilbert series, the so-called monopole formula, has been proven useful not only for 3-dimensional theories, but also for Higgs branches of 5 and 6-dimensional gauge theories with 8 supercharges. Recently, a conjecture connected different phases of 6-dimensional Higgs branches via gauging of a discrete global S n symmetry. On the corresponding 3-dimensional Coulomb branch, this amounts to a geometric S n -quotient. In this note, we prove the conjecture on Coulomb branches with unitary nodes and, moreover, extend it to Coulomb branches with other classical groups. The results promote discrete S n -quotients to a versatile tool in the study of Coulomb branches.