AbstractTwo-dimensional (2d) topological phases are characterized by a unitary modular tensor category(UMTC) along with the chiral central charge c_. For non-chiral topological phases, where c.vanishes, the topological phase is fully described by a UMTC. There are two prominent classes oflattice models that realize 2d non-chiral topological phases: (i) Kitaevs quantum double models and(il) Levi...
AbstractIn this talk, we identify a Zs discrete gravitational theta angle in the non-supersymmetricSO(16) x SO(16) heterotic string, which is detected by a 10D spacetime manifold that is anSp(2) group manifold. In the first part, we explain the string theory computation that identifies thisZ, theta angle, involving non-perturbative anomaly on the instantonic NS5 branes. in the secondpart, we mo...