{ "id": "math/0407065", "version": "v2", "published": "2004-07-05T15:24:32.000Z", "updated": "2004-09-22T19:31:32.000Z", "title": "The centralisers of nilpotent elements in classical Lie algebras", "authors": [ "O. S. Yakimova" ], "comment": "Replaced with english translation", "categories": [ "math.RT" ], "abstract": "The index of a finite-dimensional Lie algebra $g$ is the minimum of dimensions of stabilisers $g_\\alpha$ of elements $\\alpha\\in g^*$. Let $g$ be a reductive Lie algebra and $z(x)$ a centraliser of a nilpotent element $x\\in g$. Elashvili has conjectured that the index of the centraliser $z(x)$ equals the index of $g$, i.e., the rank of $g$. Here Elashvili's conjecture is proved for reductive Lie algebras of classical type. It is shown that in cases $g=gl_n$ and $g=sp_{2n}$ the coadjoint action of $z(x)$ has a generic stabiliser. Also, we give an example of a nilpotent element $x\\in so_8$ such that the coadjoint action of $z(x)$ has no generic stabiliser.", "revisions": [ { "version": "v2", "updated": "2004-09-22T19:31:32.000Z" } ], "analyses": { "keywords": [ "nilpotent element", "classical lie algebras", "centraliser", "reductive lie algebra", "generic stabiliser" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math......7065Y" } } }