English

Tensor Representations for the Drinfeld Double of the Taft Algebra

Rings and Algebras 2022-05-27 v3 Representation Theory

Abstract

Over an algebraically closed field k\mathbb k of characteristic zero, the Drinfeld double DnD_n of the Taft algebra that is defined using a primitive nnth root of unity qkq \in \mathbb k for n2n \geq 2 is a quasitriangular Hopf algebra. Kauffman and Radford have shown that DnD_n has a ribbon element if and only if nn is odd, and the ribbon element is unique; however there has been no explicit description of this element. In this work, we determine the ribbon element of DnD_n explicitly. For any n2n \geq 2, we use the R-matrix of DnD_n to construct an action of the Temperley-Lieb algebra TLk(ξ)\mathsf{TL}_k(\xi) with ξ=(q12+q12)\xi = -(q^{\frac{1}{2}}+q^{-\frac{1}{2}}) on the kk-fold tensor power VkV^{\otimes k} of any two-dimensional simple DnD_n-module VV. This action is known to be faithful for arbitrary k1k \geq 1. We show that TLk(ξ)\mathsf{TL}_k(\xi) is isomorphic to the centralizer algebra EndDn(Vk)\text{End}_{D_n}(V^{\otimes k}) for 1k2n21 \le k \le 2n-2.

Keywords

Cite

@article{arxiv.2012.15277,
  title  = {Tensor Representations for the Drinfeld Double of the Taft Algebra},
  author = {Georgia Benkart and Rekha Biswal and Ellen Kirkman and Van C. Nguyen and Jieru Zhu},
  journal= {arXiv preprint arXiv:2012.15277},
  year   = {2022}
}

Comments

27 pages, to appear in Journal of Algebra. By the referee's suggestions, starting Section 4, we shorten the paper and generalize the main results to hold for any integer $n \geq 2$. The old Sections 5 and 6 are now combined in Section 5, removing the diagrammatic arguments and extending the results to any two-dimensional simple $D_n$-module

R2 v1 2026-06-23T21:36:41.248Z