Published online by Cambridge University Press: 20 November 2018
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
 ${{A}_{2}}\,*\,{{T}_{2}}$ . We show that such quotients are parametrized by an integer   $n\,\ge \,1$  and an
 $n\,\ge \,1$  and an   $2n$ –th root of unity
 $2n$ –th root of unity   $\omega $ . We show that for
 $\omega $ . We show that for   $n\,=\,1,\,2,\,3$ , there is exactly one quotient and
 $n\,=\,1,\,2,\,3$ , there is exactly one quotient and   $\omega \,=\,1$ . For
 $\omega \,=\,1$ . For  $4\,\le \,n\,\le \,10$ , we show that there are no such quotients. Our methods also apply to quotients of
 $4\,\le \,n\,\le \,10$ , 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.
 ${{T}_{2}}\,*\,{{T}_{2}}$ , 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
 ${{A}_{2}}\,*\,{{T}_{2}}$  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.
 ${{T}_{2}}\,*\,{{T}_{2}}$ , 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
 ${{A}_{3}}$  and   ${{A}_{4}}$  subfactor planar algebras (arxiv:1308.5691). In 1994, Bisch–Haagerup showed that the principal graph of a composite of
 ${{A}_{4}}$  subfactor planar algebras (arxiv:1308.5691). In 1994, Bisch–Haagerup showed that the principal graph of a composite of   ${{A}_{3}}$  and
 ${{A}_{3}}$  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
 ${{A}_{4}}$  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   $n\,\ge \,4$ .
 $n\,\ge \,4$ .
This is an abridged version of arxiv:1308.5723.