{ "id": "1810.09115", "version": "v1", "published": "2018-10-22T07:13:46.000Z", "updated": "2018-10-22T07:13:46.000Z", "title": "Automorphism groups of almost homogeneous varieties", "authors": [ "Michel Brion" ], "comment": "21 pages", "categories": [ "math.AG" ], "abstract": "Consider a smooth connected algebraic group $G$ acting on a normal projective variety $X$ with an open dense orbit. We show that Aut($X$) is a linear algebraic group if so is $G$; for an arbitrary $G$, the group of components of Aut($X$) is arithmetic. Along the way, we obtain a restrictive condition for $G$ to be the full automorphism group of some normal projective variety.", "revisions": [ { "version": "v1", "updated": "2018-10-22T07:13:46.000Z" } ], "analyses": { "subjects": [ "14J50", "14L10", "14M17" ], "keywords": [ "homogeneous varieties", "normal projective variety", "open dense orbit", "full automorphism group", "smooth connected algebraic group" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }