{ "id": "math/0209070", "version": "v2", "published": "2002-09-06T15:56:37.000Z", "updated": "2002-10-04T00:06:14.000Z", "title": "Criteria for Irrationality of Euler's Constant", "authors": [ "Jonathan Sondow" ], "comment": "12 pages, 1 figure, 2 tables, proofs shortened & typos fixed, revised version accepted by Proc. Amer. Math. Soc", "journal": "Proc. Amer. Math. Soc. 131 (2003) 3335-3344", "categories": [ "math.NT", "math.CO" ], "abstract": "By modifying Beukers' proof of Apery's theorem that zeta(3) is irrational, we derive criteria for irrationality of Euler's constant, gamma. For n > 0, we define a double integral I(n) and a positive integer S(n), and prove that if d(n) = LCM(1,...,n), then the fractional part of logS(n) is given by {logS(n)} = d(2n)I(n), for all n sufficiently large, if and only if gamma is a rational number. A corollary is that if {logS(n)} > 1/2^n infinitely often, then gamma is irrational. Indeed, if the inequality holds for a given n (we present numerical evidence for 0 < n < 2500 and n = 10000) and gamma is rational, then its denominator does not divide the product d(2n)Binomial(2n,n). We prove a new combinatorial identity in order to show that a certain linear form in logarithms is in fact logS(n). A by-product is a rapidly converging asymptotic formula for gamma, used by P. Sebah to compute it correct to 18063 decimals.", "revisions": [ { "version": "v2", "updated": "2002-10-04T00:06:14.000Z" } ], "analyses": { "subjects": [ "11J72", "05A19" ], "keywords": [ "eulers constant", "irrationality", "aperys theorem", "rational number", "fractional part" ], "tags": [ "journal article" ], "publication": { "publisher": "AMS", "journal": "Proc. Amer. Math. Soc." }, "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2002math......9070S" } } }