What is the meaning of the Coulomb and Higgs branch for non-Lagrangian theories like the $T_N$ theories that arise as 5-brane webs and correspond to CY 3-folds in M-theory? This is related to an older question of Yuji Tach. here but no answer was given.
Is there some basic overview-review of non-Lagrangian $\mathcal{N}=2$ theories that would clearly explain the basics?
