{ "id": "1306.3251", "version": "v3", "published": "2013-06-13T20:30:27.000Z", "updated": "2014-10-08T20:51:29.000Z", "title": "On Brauer groups of double covers of ruled surfaces", "authors": [ "Brendan Creutz", "Bianca Viray" ], "comment": "v3: Sections 4-6 expanded/rewritten", "categories": [ "math.NT", "math.AG" ], "abstract": "Let X be a smooth double cover of a geometrically ruled surface defined over a separably closed field of characteristic different from 2. The main result of this paper is a finite presentation of the 2-torsion in the Brauer group of X with generators given by central simple algebras over the function field of X and relations coming from the N\\'eron-Severi group of X. In particular, the result gives a central simple algebra representative for the unique nontrivial Brauer class on any Enriques surface. An example demonstrating the applications to the study of rational points is given.", "revisions": [ { "version": "v2", "updated": "2014-03-13T03:28:22.000Z", "comment": "v2: This version replaces Part II of v1. Part I of v1 is now available as arXiv:14032924", "journal": null, "doi": null }, { "version": "v3", "updated": "2014-10-08T20:51:29.000Z" } ], "analyses": { "subjects": [ "14F22", "14G05" ], "keywords": [ "brauer group", "ruled surface", "unique nontrivial brauer class", "main result", "function field" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1306.3251C" } } }