Coulomb branches for quaternionic representations

I will review the construction of Coulomb branches in 3D gauge theory for a compact Lie group G and a quaternionic  representation E. In the case when E is polarized, these branches are determined by topological boundary conditions built from the gauged A-model of the two polar halves of E. No analogue of this is apparent in the absence of a polarization, nonetheless the Coulomb branch can be defined by the use of a ‘quantum’ square root of E (related to the Spin representation). These branches ought to be part of a 3D topological field theory, but that is only apparent in special cases.