paper

Classifying Grothendieck rings of pivotal fusion categories of rank four

arXiv:2609.33272

Abstract

We classify the Classifying Grothendieck rings of pivotal fusion categories of rank four over the complex field. There are exactly fifteen, each admitting a unitary categorification. Central induction and Frobenius-Schur indicators give a uniform Frobenius-Perron dimension bound of 3600. The finite classification combines new arithmetic and twist obstructions with an exhaustive census and exact exclusion certificates.

arXiv comment22 pages; generalized indicator and associativity lemmas; clarified sphericality and Galois reductions; revised title, exposition, tables and references; classification unchanged; code, data and exact certificates in ancillary files. Comments are welcome!