Crossed-module crossed braided categories
Abstract
For a crossed module χ: G → H, we introduce the notion of χ-crossed braided (resp. ribbon) categories, where the categories are graded by group G and carry an H-action. Our definition unifies and generalises several familiar notions: taking χ= id: G → G with the conjugation action recovers G-crossed braided categories; taking χ: G → {*} for abelian G yields G-graded braided categories; taking χ: {*} → G leads to braided categories equipped with a G-action. The equivalence relation between χ-crossed braided categories is typically finer than that between G-crossed braided ones. We classify χ-crossed braided structures on the category of G-graded vector spaces in terms of cohomological data, and give explicit examples for cyclic groups. Given a doubly central algebra with G- and H-actions in a braided monoidal category, we define a notion of twisted-local modules and show how they give rise to χ-crossed braided categories. We furthermore give sufficient conditions so that these categories are additionally χ-crossed ribbon or admit an orthogonal G-decomposition.
Related
- G-crossed braided tensor categories of twisted modules
- Affinizations and braided module categories
- Property F and weak integrality of braided fusion categories
- An Ito-Michler type theorem and the prime class graph of weakly integral braided fusion categories
- The Galois actions on braided fusion categories
BibTeX
@misc{gainutdinov2026crossedmodule,
title = {{Crossed-module crossed braided categories}},
author = {Azat M. Gainutdinov and Ingo Runkel and Bangxin Wang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.07626},
eprint = {2609.07626},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.07626},
}
RIS
TY - UNPB
TI - Crossed-module crossed braided categories
AU - Azat M. Gainutdinov
AU - Ingo Runkel
AU - Bangxin Wang
PY - 2026
DA - 2026/09/07
PB - arXiv
DO - 10.48550/arxiv.2609.07626
UR - https://arxiv.org/abs/2609.07626
AB - For a crossed module χ: G → H, we introduce the notion of χ-crossed braided (resp. ribbon) categories, where the categories are graded by group G and carry an H-action. Our definition unifies and generalises several familiar notions: taking χ= id: G → G with the conjugation action recovers G-crossed braided categories; taking χ: G → {*} for abelian G yields G-graded braided categories; taking χ: {*} → G leads to braided categories equipped with a G-action. The equivalence relation between χ-crossed braided categories is typically finer than that between G-crossed braided ones. We classify χ-crossed braided structures on the category of G-graded vector spaces in terms of cohomological data, and give explicit examples for cyclic groups. Given a doubly central algebra with G- and H-actions in a braided monoidal category, we define a notion of twisted-local modules and show how they give rise to χ-crossed braided categories. We furthermore give sufficient conditions so that these categories are additionally χ-crossed ribbon or admit an orthogonal G-decomposition.
ER -