Hostname: page-component-89b8bd64d-n8gtw Total loading time: 0 Render date: 2026-05-14T02:07:01.589Z Has data issue: false hasContentIssue false

Quotients of A 2 * T 2

Published online by Cambridge University Press:  20 November 2018

Masaki Izumi
Affiliation:
Department of Mathematics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan e-mail: izumi@math.kyoto-u.ac.jp
Scott Morrison
Affiliation:
Mathematical Sciences Institute, Australian National University, Canberra, Australia e-mail: scott.morrison@anu.edu.au
David Penneys
Affiliation:
Department of Mathematics, University of California, Los Angeles, Los Angeles, CA, 90095-1555, USA e-mail: dpenneys@math.ucla.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

We study unitary quotients of the free product unitary pivotal category ${{A}_{2}}\,*\,{{T}_{2}}$ . We show that such quotients are parametrized by an integer $n\,\ge \,1$ and an $2n$ –th root of unity $\omega $ . We show that for $n\,=\,1,\,2,\,3$ , there is exactly one quotient and $\omega \,=\,1$ . For $4\,\le \,n\,\le \,10$ , we show that there are no such quotients. Our methods also apply to quotients of ${{T}_{2}}\,*\,{{T}_{2}}$ , where we have a similar result.

The essence of our method is a consistency check on jellyfish relations. While we only treat the specific cases of ${{A}_{2}}\,*\,{{T}_{2}}$ and ${{T}_{2}}\,*\,{{T}_{2}}$ , we anticipate that our technique can be extended to a general method for proving the nonexistence of planar algebras with a specified principal graph.

During the preparation of this manuscript, we learnt of Liu's independent result on composites of ${{A}_{3}}$ and ${{A}_{4}}$ subfactor planar algebras (arxiv:1308.5691). In 1994, Bisch–Haagerup showed that the principal graph of a composite of ${{A}_{3}}$ and ${{A}_{4}}$ must fit into a certain family, and Liu has classified all such subfactor planar algebras. We explain the connection between the quotient categories and the corresponding composite subfactor planar algebras. As a corollary of Liu's result, there are no such quotient categories for $n\,\ge \,4$ .

This is an abridged version of arxiv:1308.5723.

Information

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2016