New N = 1 dualities from M5-branes and outer-automorphism twists

We generalize recent construction of four-dimensional N = 1 SCFT from wrapping six-dimensional N = (2, 0) theory on a Riemann surface to the case of D-type with outer-automorphism twists. This construction allows us to build various dual theories for a class of N = 1 quiver theories of SO-USp type. In particular, we find there are five dual frames to SO(2N)/USp(2N−2)/G 2 gauge theories with (4N−4)/(4N)/8 fundamental flavors, where three of them being non-Lagrangian. We check the dualities by computing the anomaly coefficients and the superconformal indices. In the process we verify that the index of D 4 theory on a certain three punctured sphere with Z₂ and Z₃ twist lines exhibits expected symmetry enhancement from G 2 × USp(6) to E 7.