Twisted quantum modular data and braided subfactors

Abstract

The modular data from twisted quantum double of finite groups G are studied, with cyclic groups. It is proved that the [k] and [ − k] modular data are the same up to relabelling of the primary fields and complex conjugation of the underlying representation of the modular group . Then we produce some lower bounds for the number of modular invariants of these models, and complete the study for the cases and at all twists, proving in particular that all their modular invariants are produced by braided subfactors.