{ "id": "2010.06852", "version": "v1", "published": "2020-10-14T07:36:24.000Z", "updated": "2020-10-14T07:36:24.000Z", "title": "Some homological properties of category $\\mathcal O$ for Lie superalgebras", "authors": [ "Chih-Whi Chen", "Volodymyr Mazorchuk" ], "comment": "25 pages", "categories": [ "math.RT" ], "abstract": "For classical Lie superalgebras of type I, we provide necessary and sufficient conditions for a Verma supermodule $\\Delta(\\lambda)$ to be such that every non-zero homomorphism from another Verma supermodule to $\\Delta(\\lambda)$ is injective. This is applied to describe the socle of the cokernel of an inclusion of Verma supermodules over the periplectic Lie superalgebras $\\mathfrak{pe}(n)$ and, furthermore, to reduce the problem of description of $\\mathrm{Ext}^1_{\\mathcal O}(L(\\mu),\\Delta(\\lambda))$ for $\\mathfrak{pe}(n)$ to the similar problem for the Lie algebra $\\mathfrak{gl}(n)$. Additionally, we study the projective and injective dimensions of structural supermodules in parabolic category $\\mathcal O^{\\mathfrak p}$ for classical Lie superalgebras. In particular, we completely determine these dimensions for structural supermodules over the periplectic Lie superalgebra $\\mathfrak{pe}(n)$ and the ortho-symplectic Lie superalgebra $\\mathfrak{osp}(2|2n)$.", "revisions": [ { "version": "v1", "updated": "2020-10-14T07:36:24.000Z" } ], "analyses": { "subjects": [ "17B10", "17B55" ], "keywords": [ "homological properties", "verma supermodule", "periplectic lie superalgebra", "classical lie superalgebras", "structural supermodules" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable" } } }