The Brauer-Picard groups of the fusion categories coming from the subfactors
arXiv:1709.04721
Abstract
We compute the group of Morita auto-equivalences of the even parts of the subfactors, and Galois conjugates. To achieve this we study the braided auto-equivalences of the Drinfeld centres of these categories. We give planar algebra presentations for each of these Drinfeld centres, which we leverage to obtain information about the braided auto-equivalences of the corresponding categories. We also perform the same calculations for the fusion categories constructed from the full subfactors. Of particular interest, the even part of the subfactor is shown to have Brauer-Picard group . We develop combinatorial arguments to compute the underlying algebra objects of these invertible bimodules.
Version 2: Major changes in section 4 and minor changes elsewhere, change of title