On the torus compactifications of Z2 orbifolds of E-string theories

A bstract We consider the torus compactifications with flux of a class of 6 d (1, 0) SCFTs that can be engineered as the low-energy theories on M5-branes near an M9-plane on a C 2 / Z 2 singularity. Specifically, we concentrate on the two SCFTs where the Z 2 orbifold action acts non-trivially on the E 8 global symmetry. We analyze this problem by compactifying to 5 d , where we can exploit the relation to 5 d duality domain walls. By a suitable guess of the domain wall theories, the resulting 4 d theories can be conjectured. These can then be tested by comparing their properties, notably anomalies and symmetries, against the 6 d expectations. These constructions lead to various interesting 4 d phenomena like dualities and symmetry enhancements.