“…The 4d duality implies the genus is symmetric under c ↔ d, or, in more standard notation, that the U(1) B baryon symmetry maps to itself with a change of sign, with all other flavor symmetries fixed. This gives evidence for a N = (2, 2) duality, which was noticed also in [23]. Note that, since the theories have N = (2, 2) supersymmetry, we can also compute their S 2 partition functions as a function of twisted masses for the flavor symmetries, which comprises an independent check of this duality.…”