Good IR Duals of Bad Quiver Theories

TL;DR

This paper explores the infrared behavior of 3d N=4 bad theories, providing an explicit example where a bad quiver theory admits a good IR description involving decoupled quivers, enhancing understanding of their IR fixed points.

Contribution

It presents a specific bad quiver gauge theory that has a good IR description on a sublocus of its Coulomb branch, illustrating a new class of IR fixed points.

Findings

A bad quiver theory admits a good IR description on a Coulomb branch sublocus.

The good IR description involves two decoupled quiver gauge theories.

No free hypermultiplets are present in the IR description.

Abstract

The infrared dynamics of generic 3d N=4 bad theories (as per the good-bad-ugly classification of Gaiotto and Witten) are poorly understood. Examples of such theories with a single unitary gauge group and fundamental flavors have been studied recently, and the low energy effective theory around some special point in the Coulomb branch was shown to have a description in terms of a good theory and a certain number of free hypermultiplets. A classification of possible infrared fixed points for bad theories by Bashkirov, based on unitarity constraints and superconformal symmetry, suggest a much richer set of possibilities for the IR behavior, although explicit examples were not known. In this note, we present a specific example of a bad quiver gauge theory which admits a good IR description on a sublocus of its Coulomb branch. The good description, in question, consists of two decoupled quiver gauge theories with no free hypermultiplets.