English

Frobenius monoidal functors from (co)Hopf adjunctions

Quantum Algebra 2023-03-28 v2 Category Theory

Abstract

Let U:CDU:\mathcal{C}\rightarrow\mathcal{D} be a strong monoidal functor between abelian monoidal categories admitting a right adjoint RR, such that RR is exact, faithful and the adjunction URU\dashv R is coHopf. Building on the work of Balan, we show that RR is separable (resp., special) Frobenius monoidal if and only if R(1D)R(\mathbb{1}_{\mathcal{D}}) is a separable (resp., special) Frobenius algebra in C\mathcal{C}. If further, C,D\mathcal{C},\mathcal{D} are pivotal (resp., ribbon) categories and UU is a pivotal (resp., braided pivotal) functor, then RR is a pivotal (resp., ribbon) functor if and only if R(1D)R(\mathbb{1}_{\mathcal{D}}) is a symmetric Frobenius algebra in C\mathcal{C}. As an application, we construct Frobenius monoidal functors going into the Drinfeld center Z(C)\mathcal{Z}(\mathcal{C}), thereby producing Frobenius algebras in it.

Keywords

Cite

@article{arxiv.2209.15606,
  title  = {Frobenius monoidal functors from (co)Hopf adjunctions},
  author = {Harshit Yadav},
  journal= {arXiv preprint arXiv:2209.15606},
  year   = {2023}
}

Comments

v2: 16 pages. Corrected the proof of Theorem 3.13. Final version, to appear in Proceedings of the AMS

R2 v1 2026-06-28T02:28:37.107Z