{ "id": "0910.4448", "version": "v1", "published": "2009-10-23T06:39:34.000Z", "updated": "2009-10-23T06:39:34.000Z", "title": "Irrationality exponent and rational approximations with prescribed growth", "authors": [ "Stéphane Fischler", "Tanguy Rivoal" ], "comment": "11 pages, to appear in Proc. Amer. Math. Soc", "journal": "Proc. Amer. Math. Soc. 138.8 (2010), 799-808", "categories": [ "math.NT" ], "abstract": "Let $\\xi$ be a real irrational number. We are interested in sequences of linear forms in 1 and $\\xi$, with integer coefficients, which tend to 0. Does such a sequence exist such that the linear forms are small (with given rate of decrease) and the coefficients have some given rate of growth? If these rates are essentially geometric, a necessary condition for such a sequence to exist is that the linear forms are not too small, a condition which can be expressed precisely using the irrationality exponent of $\\xi$. We prove that this condition is actually sufficient, even for arbitrary rates of growth and decrease. We also make some remarks and ask some questions about multivariate generalizations connected to Fischler-Zudilin's new proof of Nesterenko's linear independence criterion.", "revisions": [ { "version": "v1", "updated": "2009-10-23T06:39:34.000Z" } ], "analyses": { "subjects": [ "11J82", "11J04", "11J13", "11J72" ], "keywords": [ "irrationality exponent", "rational approximations", "prescribed growth", "linear forms", "nesterenkos linear independence criterion" ], "tags": [ "journal article" ], "publication": { "publisher": "AMS", "journal": "Proc. Amer. Math. Soc." }, "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0910.4448F" } } }