4d N = 2 gauge theories and quivers: The non-simply laced case

We construct the BPS quivers with superpotential for the 4d N = 2 gauge theories with non-simply laced Lie groups (B n, C n, F 4 and G 2). The construction is inspired by the BIKMSV geometric engineering of these gauge groups as non-split singular elliptic fibrations. From the categorical viewpoint of arXiv:1203.6734, the fibration of the light category L (g) over the (degenerate) Gaiotto curve has a monodromy given by the action of the outer automorphism of the corresponding unfolded Lie algebra. In view of the Katz-Vafa 'matter from geometry' mechanism, the monodromic idea may be extended to the construction of (Q,W) for SYM coupled to higher matter representations. This is done through a construction we call specialization. © 2012 SISSA.