{ "id": "2010.04358", "version": "v1", "published": "2020-10-09T03:56:48.000Z", "updated": "2020-10-09T03:56:48.000Z", "title": "Abelian Ideals and the Variety of Lagrangian Subalgebras", "authors": [ "Sam Evens", "Yu Li" ], "categories": [ "math.RT", "math.AG", "math.SG" ], "abstract": "For a semisimple algebraic group $G$ of adjoint type with Lie algebra $\\mathfrak g$ over the complex numbers, we establish a bijection between the set of closed orbits of the group $G \\ltimes \\mathfrak g^{\\ast}$ acting on the variety of Lagrangian subalgebras of $\\mathfrak g \\ltimes \\mathfrak g^{\\ast}$ and the set of abelian ideals of a fixed Borel subalgebra of $\\mathfrak g$. In particular, the number of such orbits equals $2^{\\text{rk} \\mathfrak g}$ by Peterson's theorem on abelian ideals.", "revisions": [ { "version": "v1", "updated": "2020-10-09T03:56:48.000Z" } ], "analyses": { "keywords": [ "abelian ideals", "lagrangian subalgebras", "semisimple algebraic group", "adjoint type", "petersons theorem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }