{ "id": "0812.4275", "version": "v2", "published": "2008-12-22T20:06:18.000Z", "updated": "2010-06-30T15:05:25.000Z", "title": "Quasi-reductive (bi)parabolic subalgebras in reductive Lie algebras", "authors": [ "Karin Baur", "Anne Moreau" ], "comment": "20 pages", "journal": "Annales de l'Institut Fourier 61, 2 (2011) 417-451", "categories": [ "math.RT" ], "abstract": "We say that a finite dimensional Lie algebra is quasi-reductive if it has a linear form whose stabilizer for the coadjoint representation, modulo the center, is a reductive Lie algebra with a center consisting of semisimple elements. Parabolic subalgebras of a semisimple Lie algebra are not always quasi-reductive (except in types A or C by work of Panyushev). The classification of quasi-reductive parabolic subalgebras in the classical case has been recently achieved in unpublished work of Duflo, Khalgui and Torasso. In this paper, we investigate the quasi-reductivity of biparabolic subalgebras of reductive Lie algebras. Biparabolic (or seaweed) subalgebras are the intersection of two parabolic subalgebras whose sum is the total Lie algebra. As a main result, we complete the classification of quasi-reductive parabolic subalgebras of reductive Lie algebras by considering the exceptional cases.", "revisions": [ { "version": "v2", "updated": "2010-06-30T15:05:25.000Z" } ], "analyses": { "keywords": [ "reductive lie algebra", "quasi-reductive parabolic subalgebras", "finite dimensional lie algebra", "semisimple lie algebra", "total lie algebra" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0812.4275B" } } }