The Brauer-Picard group of the Asaeda-Haagerup fusion categories

TL;DR

This paper determines the Brauer-Picard group of certain fusion categories related to the Asaeda-Haagerup subfactor, classifies associated bimodule categories and subfactors, and explores potential additional fusion categories.

Contribution

It explicitly computes the Brauer-Picard group for these categories and classifies all related irreducible subfactors, providing new insights into their structure and potential extensions.

Findings

Brauer-Picard group is the Klein four-group

36 bimodule categories described within the groupoid

111 irreducible subfactors classified up to isomorphism

Abstract

We prove that the Brauer-Picard group of Morita autoequiv- alences of each of the three fusion categories which arise as an even part of the Asaeda-Haagerup subfactor or of its index 2 extension is the Klein four-group. We describe the 36 bimodule categories which occur in the full subgroupoid of the Brauer-Picard groupoid on these three fusion categories. We also classify all irreducible subfactors both of whose even parts are among these categories, of which there are 111 up to isomorphism of the planar algebra (76 up to duality). Although we identify the entire Brauer-Picard group, there may be additional fusion categories in the groupoid. We prove a partial classification of possible additional fusion categories Morita equivalent to the Asaeda-Haagerup fusion categories and make some conjectures about their existence; we hope to address these conjectures in future work.