English

Modular categories with transitive Galois actions

Quantum Algebra 2022-04-12 v3 Category Theory

Abstract

In this paper, we study modular categories whose Galois group actions on their simple objects are transitive. We show that such modular categories admit unique factorization into prime transitive factors. The representations of SL2(Z)SL_2(\mathbb{Z}) associated with transitive modular categories are proven to be minimal and irreducible. Together with the Verlinde formula, we characterize prime transitive modular categories as the Galois conjugates of the adjoint subcategory of the quantum group modular category C(sl2,p2)\mathcal{C}(\mathfrak{sl}_2,p-2) for some prime p>3p > 3. As a consequence, we completely classify transitive modular categories. Transitivity of super-modular categories can be similarly defined. A unique factorization of any transitive super-modular category into s-simple transitive factors is obtained, and the split transitive super-modular categories are completely classified.

Keywords

Cite

@article{arxiv.2007.01366,
  title  = {Modular categories with transitive Galois actions},
  author = {Siu-Hung Ng and Yilong Wang and Qing Zhang},
  journal= {arXiv preprint arXiv:2007.01366},
  year   = {2022}
}

Comments

Minor errors in proposition 5.11 and the associated parts in this version of the paper have been corrected

R2 v1 2026-06-23T16:48:50.451Z