{ "id": "2111.02077", "version": "v2", "published": "2021-11-03T08:59:30.000Z", "updated": "2022-02-09T08:56:08.000Z", "title": "Periodicity for subquotients of the modular category $\\mathcal{O}$", "authors": [ "Peter Fiebig" ], "comment": "14 pages; second version without essential changes", "categories": [ "math.RT" ], "abstract": "In this paper we study the category $\\mathcal{O}$ over the hyperalgebra of a reductive algebraic group in positive characteristics. For any locally closed subset $\\mathcal{K}$ of weights we define a subquotient $\\mathcal{O}_{[\\mathcal{K}]}$ of $\\mathcal{O}$. It has the property that its simple objects are parametrized by elements in $\\mathcal{K}$. We then show that $\\mathcal{O}_{[\\mathcal{K}]}$ is equivalent to $\\mathcal{O}_{[\\mathcal{K}+p^l\\gamma]}$ for any dominant weight $\\gamma$ if $l>0$ is an integer such that $\\mathcal{K}\\cap (\\mathcal{K}+p^l\\eta)=\\emptyset$ for all dominant weights $\\eta$. This allows one, for example, to restrict attention to subquotients inside the dominant (or the antidominant) chamber.", "revisions": [ { "version": "v2", "updated": "2022-02-09T08:56:08.000Z" } ], "analyses": { "keywords": [ "modular category", "periodicity", "dominant weight", "simple objects", "reductive algebraic group" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }