Probing bad theories with the dualization algorithm. Part I

Abstract

Abstract Recently an algorithm to build SL(2, ℤ) duals, including mirror duals, of 3d $$ \mathcal{N} $$ N = 4 quiver theories and their 4d $$ \mathcal{N} $$ N = 1 uplift has been introduced. In this work we use this new tool to study the so-called bad theories. Our approach allows us to determine exactly indices/partition functions for generic values of fugacities/real mass and FI parameters revealing their surprising feature: the 4d index/3d partition function of a bad theory behaves as a sum of distributions rather than an ordinary function of the deformation parameters. We focus on the bad SQCD, with U(Nc) gauge group in 3d and USp(2Nc) in 4d, while in an upcoming paper we will consider linear quivers which, in the 3d case, have both unitary and special unitary bad nodes.