Dualities for adjoint SQCD in three dimensions and emergent symmetries

In this paper we study dualities for N = 2 gauge theories in three dimensions with matter in the fundamental and adjoint representation. The duality we propose, analogous to mirror symmetry, is obtained starting from N = 4 mirror theories and turning on a certain superpotential deformation involving monopole operators. We study the role of emergent symmetries in the dual theory, focusing on the case of models with gauge symmetry U(2) or SU(2). We find that SU(2) adjoint SQCD with one flavor and zero superpotential is dual to SQED with two flavors and three singlets. As a byproduct, we recover several dualities for theories with N = 2 and N = 4 supersymmetry, including the duality appetizer of Jafferis and Yin.