{ "id": "1904.13040", "version": "v1", "published": "2019-04-30T03:47:14.000Z", "updated": "2019-04-30T03:47:14.000Z", "title": "Jantzen filtration of Weyl modules, product of Young symmetrizers and denominator of Young's seminormal basis", "authors": [ "Ming Fang", "Kay Jin Lim", "Kai Meng Tan" ], "categories": [ "math.RT" ], "abstract": "Let $G$ be a connected reductive algebraic group over an algebraically closed field of characteristic $p>0$, $\\Delta(\\lambda)$ denote the Weyl module of $G$ of highest weight $\\lambda$ and $\\iota_{\\lambda,\\mu}:\\Delta(\\lambda+\\mu)\\to \\Delta(\\lambda)\\otimes\\Delta(\\mu)$ be the canonical $G$-morphism. We study the split condition for $\\iota_{\\lambda,\\mu}$ over $\\mathbb{Z}_{(p)}$, and apply this as an approach to compare the Jantzen filtrations of the Weyl modules $\\Delta(\\lambda)$ and $\\Delta(\\lambda+\\mu)$. In the case when $G$ is of type $A$, we show that the split condition is closely related to the product of certain Young symmetrizers and is further characterized by the denominator of a certain Young's seminormal basis vector in certain cases. We obtain explicit formulas for the split condition in some cases.", "revisions": [ { "version": "v1", "updated": "2019-04-30T03:47:14.000Z" } ], "analyses": { "subjects": [ "20G05", "20C30" ], "keywords": [ "weyl module", "young symmetrizers", "jantzen filtration", "split condition", "denominator" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }