{ "id": "1112.3089", "version": "v1", "published": "2011-12-14T01:10:40.000Z", "updated": "2011-12-14T01:10:40.000Z", "title": "The Brauer group and the Brauer-Manin set of products of varieties", "authors": [ "Alexei N. Skorobogatov", "Yuri G. Zarhin" ], "comment": "20 pages", "categories": [ "math.AG", "math.NT" ], "abstract": "Let $X$ and $Y$ be smooth and projective varieties over a field $k$ finitely generated over $\\mathbb Q$, and let $\\ov X$ and $\\ov Y$ be the varieties over an algebraic closure of $k$ obtained from $X$ and $Y$, respectively, by extension of the ground field. We show that the Galois invariant subgroup of $\\Br(\\ov X)\\oplus \\Br(\\ov Y)$ has finite index in the Galois invariant subgroup of $\\Br(\\ov X\\times\\ov Y)$. This implies that the cokernel of the natural map $\\Br(X)\\oplus\\Br(Y)\\to\\Br(X\\times Y)$ is finite when $k$ is a number field. In this case we prove that the Brauer-Manin set of the product of varieties is the product of their Brauer-Manin sets.", "revisions": [ { "version": "v1", "updated": "2011-12-14T01:10:40.000Z" } ], "analyses": { "subjects": [ "14F22", "14G25" ], "keywords": [ "brauer-manin set", "brauer group", "galois invariant subgroup", "number field", "natural map" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1112.3089S" } } }