English

Tannaka-Krein duality for finite 2-groups

Quantum Algebra 2025-07-22 v3 Category Theory Representation Theory

Abstract

Let G\mathcal{G} be a finite 2-group. We show that the 2-category 2Rep(G)2\mathrm{Rep}(\mathcal{G}) of finite semisimple 2-representations is a symmetric fusion 2-category. We also relate the auto-equivalence 2-group of the symmetric monoidal forgetful 2-functor ω:2Rep(G)2Vec\omega : 2\mathrm{Rep}(\mathcal{G}) \to 2\mathrm{Vec} to the auto-equivalence 2-group of the regular algebra and show that they are equivalent to G\mathcal{G}. This result categorifies the usual Tannaka-Krein duality for finite groups.

Keywords

Cite

@article{arxiv.2305.18151,
  title  = {Tannaka-Krein duality for finite 2-groups},
  author = {Mo Huang and Zhi-Hao Zhang},
  journal= {arXiv preprint arXiv:2305.18151},
  year   = {2025}
}

Comments

25 pages. Add more resuts on Hopf monoidal structures of Vec_G and Fun(G,Vec). Comments are welcome

R2 v1 2026-06-28T10:49:20.849Z