{ "id": "1502.04867", "version": "v1", "published": "2015-02-17T11:39:05.000Z", "updated": "2015-02-17T11:39:05.000Z", "title": "Highest weight vectors and transmutation", "authors": [ "Rudolf Tange" ], "categories": [ "math.RT" ], "abstract": "Let $G={\\rm GL}_n$ be the general linear group over an algebraically closed field $k$, let $\\mathfrak g=\\mathfrak gl_n$ be its Lie algebra and let $U$ be the subgroup of $G$ which consists of the upper uni-triangular matrices. Let $k[\\mathfrak g]$ be the algebra of polynomial functions on $\\mathfrak g$ and let $k[\\mathfrak g]^G$ be the algebra of invariants under the conjugation action of $G$. In characteristic zero, we give for all dominant weights $\\chi\\in\\mathbb Z^n$ finite homogeneous spanning sets for the $k[\\mathfrak g]^G$-modules $k[\\mathfrak g]_\\chi^U$ of highest weight vectors. This result (with some mistakes) was already given without proof by J.~F.~Donin. Then we do the same for tuples of $n\\times n$-matrices under the diagonal conjugation action. Furthermore we extend our earlier results in positive characteristic and give a general result which reduces the problem to giving spanning sets of the highest weight vectors for the action of ${\\rm GL}_r\\times{\\rm GL}_s$ on tuples of $r\\times s$ matrices. This requires the technique called \"transmutation\" by R.~Brylinsky which is based on an instance of Howe duality. In the cases that $\\chi_{{}_n}\\ge -1$ or $\\chi_{{}_1}\\le 1$ this leads to new spanning sets for the modules $k[\\mathfrak g]_\\chi^U$.", "revisions": [ { "version": "v1", "updated": "2015-02-17T11:39:05.000Z" } ], "analyses": { "keywords": [ "highest weight vectors", "transmutation", "spanning sets", "general linear group", "diagonal conjugation action" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }