{ "id": "1305.5429", "version": "v2", "published": "2013-05-23T14:16:35.000Z", "updated": "2013-05-24T17:39:03.000Z", "title": "Gaussian Mills ratio is completely monotone", "authors": [ "Armengol Gasull", "Frederic Utzet" ], "comment": "This paper has been withdrawn by the authors due that the results appear in Arpad Baricz. Mills'ratio: Monotonicity patterns and functional inequalities. Journal of Mathematical Analysis and Applications, 340 (2008) 1362-1370 M. R. Sampford. Inequalities on Mill's ratio and related functions, The Annals of Mathematical Statistics, Vol. 24, No. 1 (1953) 130-132", "categories": [ "math.PR" ], "abstract": "Consider the Mills ratio corresponding to the standard Gaussian law, $f(x)=\\big(1-\\Phi(x)\\big)/\\phi(x), \\, x\\ge 0$, where $\\phi$ is the density function of this law and $\\Phi$ its cumulative distribution function. We prove that this function is completely monotone. In the proof we obtain a sequence of rational functions that are sharp bounds for $f$; it turns out that these rational functions are the convergents of the continued fraction defined by $f$, and provide an approximation procedure that allows to prove interesting properties where $f$ or its derivatives are involved. As an application we show that $1/f$ is strictly convex.", "revisions": [ { "version": "v2", "updated": "2013-05-24T17:39:03.000Z" } ], "analyses": { "keywords": [ "gaussian mills ratio", "rational functions", "standard gaussian law", "density function", "approximation procedure" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1305.5429G" } } }