{ "id": "0902.3093", "version": "v1", "published": "2009-02-18T10:43:15.000Z", "updated": "2009-02-18T10:43:15.000Z", "title": "Upper bounds for the order of an additive basis obtained by removing a finite subset of a given basis", "authors": [ "Bakir Farhi" ], "comment": "17 pages", "journal": "J. Number Theory, 128 (2008), p. 2214-2230", "categories": [ "math.NT", "math.CO" ], "abstract": "Let $A$ be an additive basis of order $h$ and $X$ be a finite nonempty subset of $A$ such that the set $A \\setminus X$ is still a basis. In this article, we give several upper bounds for the order of $A \\setminus X$ in function of the order $h$ of $A$ and some parameters related to $X$ and $A$. If the parameter in question is the cardinality of $X$, Nathanson and Nash already obtained some of such upper bounds, which can be seen as polynomials in $h$ with degree $(|X| + 1)$. Here, by taking instead of the cardinality of $X$ the parameter defined by $d := \\frac{\\diam(X)}{\\gcd\\{x - y | x, y \\in X\\}}$, we show that the order of $A \\setminus X$ is bounded above by $(\\frac{h (h + 3)}{2} + d \\frac{h (h - 1) (h + 4)}{6})$. As a consequence, we deduce that if $X$ is an arithmetic progression of length $\\geq 3$, then the upper bounds of Nathanson and Nash are considerably improved. Further, by considering more complex parameters related to both $X$ and $A$, we get upper bounds which are polynomials in $h$ with degree only 2.", "revisions": [ { "version": "v1", "updated": "2009-02-18T10:43:15.000Z" } ], "analyses": { "subjects": [ "11B13" ], "keywords": [ "upper bounds", "additive basis", "finite subset", "finite nonempty subset", "complex parameters" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0902.3093F" } } }