{ "id": "0905.4647", "version": "v2", "published": "2009-05-28T13:35:37.000Z", "updated": "2010-01-30T17:48:25.000Z", "title": "Group actions on affine cones", "authors": [ "Takashi Kishimoto", "Yuri Prokhorov", "Mikhail Zaidenberg" ], "comment": "41p", "categories": [ "math.AG" ], "abstract": "We address the following question: Determine the affine cones over smooth projective varieties which admit an action of a connected algebraic group different from the standard C*-action by scalar matrices and its inverse action. We show in particular that the affine cones over anticanonically embedded smooth del Pezzo surfaces of degree at least 4 possess such an action. A question by Flenner and the third author whether this is also true for cubic surfaces, occurs to be out of reach for our methods. Nevertheless, we provide a general geometric criterion that could be helpful also in this case.", "revisions": [ { "version": "v2", "updated": "2010-01-30T17:48:25.000Z" } ], "analyses": { "subjects": [ "14R20", "13A50", "14L30" ], "keywords": [ "affine cones", "group actions", "embedded smooth del pezzo surfaces", "anticanonically embedded smooth del pezzo", "general geometric criterion" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0905.4647K" } } }