English

A brief history of the positivity conjecture in tensor category theory

Quantum Algebra 2017-03-28 v1

Abstract

We show the existence of a finite group GG having an irreducible character χ\chi with Frobenius-Schur indicator ν2(χ)=+1\nu_2(\chi){=}{+}1 such that χ2\chi^2 has an irreducible constituent φ\varphi with ν2(φ)=1\nu_2(\varphi){=}{-}1. This provides counterexamples to the positivity conjecture in rational CFT and a conjecture of Zhenghan Wang about pivotal fusion categories.

Keywords

Cite

@article{arxiv.1703.08890,
  title  = {A brief history of the positivity conjecture in tensor category theory},
  author = {Geoffrey Mason},
  journal= {arXiv preprint arXiv:1703.08890},
  year   = {2017}
}

Comments

This is version includes needed corrections pointed out by an Arxiv editor. I have no idea how to get a local report number!