Hopf $2$-cocycles for certain affine algebraic reductive groups
Abstract
Motivated by the open problem of classifying Hopf -cocycles for affine algebraic reductive groups over , in particular by \cite[Question 7.2]{EG1} which concerns minimal Hopf -cocycles, we classify (minimal) Hopf -cocycles for affine algebraic reductive groups whose connected component of the identity is a torus . To achieve this we utilize \cite[Proposition 5.4]{ENO} in our situation to classify finite indecomposable semisimple module categories over the infinite semisimple equivariantization tensor category , where . We then use it to classify the module categories over of rank , and show that the corresponding fiber functors on are classical (that is, preserve dimensions), which implies that they are in bijection with Hopf -cocycles for .
Cite
@article{arxiv.2607.18599,
title = {Hopf $2$-cocycles for certain affine algebraic reductive groups},
author = {Shlomo Gelaki},
journal= {arXiv preprint arXiv:2607.18599},
year = {2026}
}
Comments
25 pages