Unifying the 6D $$ \mathcal{N} $$ = (1, 1) string landscape

A bstract We propose an organizing principle for string theory moduli spaces in six dimensions with $$ \mathcal{N} N = (1, 1), based on a rank reduction map, into which all known constructions fit. In the case of cyclic orbifolds, are main focus paper, we make explicit connection meromorphic 2D (s)CFTs c 24 ( 12) and show how these encode every possible gauge symmetry enhancement their associated 6D theories. These results generalize naturally to non-cyclic only construction (to our awareness) also fits. This framework suggests existence total 47 spaces: Narain space, 23 orbifold type type. Of 17 have constructions. Among 30 new spaces, 15 correspond pure supergravity, 16 such spaces. full classification nonabelian symmetries is given, as byproduct complete one seven dimensions, those theories heterotic descriptions were exhaustively.