String theory on G2 manifolds based on Gepner construction Original Research Article

We study the type II string theories compactified on manifolds of G2 holonomy of the type (Calabi–Yau 3-fold×S1)/Z2 where CY3 sectors realized by the Gepner models. We construct modular invariant partition functions for G2 manifold for arbitrary Gepner models of the Calabi–Yau sector. We note that the conformal blocks contain the tricritical Ising model and find extra massless states in the twisted sectors of the theory when all the levels ki of minimal models in Gepner constructions are even.