spherical category

{{Primary sources|date=November 2013}}

In category theory, a branch of mathematics, a spherical category is a pivotal category (a monoidal category with traces) in which left and right traces coincide.{{cite journal|journal=Advances in Mathematics|volume=143|issue=2|pages=357–375|year=1999|title=Spherical Categories|author=John W. Barrett |author2=Bruce W. Westbury |doi=10.1006/aima.1998.1800|doi-access=free|arxiv=hep-th/9310164}}

Spherical fusion categories give rise to a family of three-dimensional topological state sum models (a particular formulation of a topological quantum field theory), the Turaev-Viro model, or rather Turaev-Viro-Barrett-Westbury model.{{cite web|title=Turaev-Viro model|url=https://ncatlab.org/nlab/show/Turaev-Viro+model|website=nLab|access-date=7 August 2017}}