Cyclic extensions of fusion categories via the Brauer–Picard groupoid
Cyclic extensions of fusion categories via the Brauer–Picard groupoid
We construct a long exact sequence computing the obstruction space, \pi_1\mathrm {BrPic}(\mathcal C_0) , to G -graded extensions of a fusion category \mathcal C_0 . The other terms in the\linebreak sequence can be computed directly from the fusion ring of \mathcal C_0 . We apply our result to several examples …