{ "id": "1302.2377", "version": "v3", "published": "2013-02-10T23:07:21.000Z", "updated": "2015-09-20T20:35:49.000Z", "title": "Lois de réciprocité supérieures et points rationnels", "authors": [ "Jean-Louis Colliot-Thélène", "Raman Parimala", "Venapally Suresh" ], "comment": "Final version, in French, to appear in the Transactions of the American Mathematical Society", "categories": [ "math.AG", "math.NT" ], "abstract": "Let C be the complex field and K=C((x,y)) or K=C((x))(y). Let G be a connected linear algebraic group over K. Under the assumption that the K-variety G is K-rational, i.e. that the function field is purely transcendant, it was proved that a principal homogeneous space of G has a rational point over K as soon as it has one over each completion of K with respect to a discrete valuation. In this paper we show that one cannot in general do without the K-rationality assumption. To produce our examples, we introduce a new type of obstruction. It is based on higher reciprocity laws on a 2-dimensional scheme. We also produce a family of principal homogeneous spaces for which the refined obstruction controls exactly the existence of rational points.", "revisions": [ { "version": "v2", "updated": "2013-11-22T19:36:18.000Z", "comment": "Slightly revised, 22nd november 2013", "journal": null, "doi": null }, { "version": "v3", "updated": "2015-09-20T20:35:49.000Z" } ], "analyses": { "subjects": [ "11G99", "14G99", "11E72", "14F22" ], "keywords": [ "points rationnels", "principal homogeneous space", "rational point", "supérieures", "connected linear algebraic group" ], "note": { "typesetting": "TeX", "pages": 0, "language": "fr", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1302.2377C" } } }