{ "id": "1002.2209", "version": "v1", "published": "2010-02-10T20:51:19.000Z", "updated": "2010-02-10T20:51:19.000Z", "title": "Linear forms and quadratic uniformity for functions on $\\mathbb{F}_p^n$", "authors": [ "W. T. Gowers", "J. Wolf" ], "comment": "26 pages", "doi": "10.1112/S0025579311001264", "categories": [ "math.NT", "math.CO" ], "abstract": "We give improved bounds for our theorem in [GW09], which shows that a system of linear forms on $\\mathbb{F}_p^n$ with squares that are linearly independent has the expected number of solutions in any linearly uniform subset of $\\mathbb{F}_p^n$. While in [GW09] the dependence between the uniformity of the set and the resulting error in the average over the linear system was of tower type, we now obtain a doubly exponential relation between the two parameters. Instead of the structure theorem for bounded functions due to Green and Tao [GrT08], we use the Hahn-Banach theorem to decompose the function into a quadratically structured plus a quadratically uniform part. This new decomposition makes more efficient use of the $U^3$ inverse theorem [GrT08].", "revisions": [ { "version": "v1", "updated": "2010-02-10T20:51:19.000Z" } ], "analyses": { "subjects": [ "11B30" ], "keywords": [ "linear forms", "quadratic uniformity", "quadratically uniform part", "hahn-banach theorem", "structure theorem" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1002.2209G" } } }