English

Module categories over affine supergroup schemes

Quantum Algebra 2021-01-26 v2

Abstract

Let kk be an algebraically closed field of characteristic 00 or p>2p>2. Let G\mathcal{G} be an affine supergroup scheme over kk. We classify the indecomposable exact module categories over the tensor category sCohf(G){\rm sCoh}_{\rm f}(\mathcal{G}) of (coherent sheaves of) finite dimensional O(G)\mathcal{O}(\mathcal{G})-supermodules in terms of (H,Ψ)(\mathcal{H},\Psi)-equivariant coherent sheaves on G\mathcal{G}. We deduce from it the classification of indecomposable {\em geometrical} module categories over \sRep(G)\sRep(\mathcal{G}). When G\mathcal{G} is finite, this yields the classification of {\em all} indecomposable exact module categories over the finite tensor category \sRep(G)\sRep(\mathcal{G}). In particular, we obtain a classification of twists for the supergroup algebra kGk\mathcal{G} of a finite supergroup scheme G\mathcal{G}, and then combine it with \cite[Corollary 4.1]{EG3} to classify finite dimensional triangular Hopf algebras with the Chevalley property over kk.

Keywords

Cite

@article{arxiv.1909.10908,
  title  = {Module categories over affine supergroup schemes},
  author = {Shlomo Gelaki},
  journal= {arXiv preprint arXiv:1909.10908},
  year   = {2021}
}

Comments

24 pages, added Lemma 5.4, to appear in JPAA. arXiv admin note: text overlap with arXiv:1209.1155

R2 v1 2026-06-23T11:24:18.507Z