{ "id": "1405.4747", "version": "v2", "published": "2014-05-19T14:37:19.000Z", "updated": "2015-10-28T16:38:47.000Z", "title": "Subexponentially increasing sum of partial quotients in continued fraction expansions", "authors": [ "Lingmin Liao", "Michal Rams" ], "comment": "11 pages", "categories": [ "math.DS" ], "abstract": "We investigate from multifractal analysis point of view the increasing rate of the sum of partial quotients $S\\_n(x)=\\sum\\_{j=1}^n a\\_j(x)$, where $x=[a\\_1(x), a\\_2(x), \\cdots ]$ is the continued fraction expansion of an irrational $x\\in (0,1)$. Precisely, for an increasing function $\\varphi: \\mathbb{N} \\rightarrow \\mathbb{N}$, one is interested in the Hausdorff dimension of the sets \\[ E\\_\\varphi = \\left\\{x\\in (0,1): \\lim\\_{n\\to\\infty} \\frac {S\\_n(x)} {\\varphi(n)} =1\\right\\}. \\] Several cases are solved by Iommi and Jordan, Wu and Xu, and Xu. We attack the remaining subexponential case $\\exp(n^\\beta), \\ \\beta \\in [1/2, 1)$. We show that when $\\beta \\in [1/2, 1)$, $E\\_\\varphi$ has Hausdorff dimension $1/2$. Thus surprisingly the dimension has a jump from $1$ to $1/2$ at the increasing rate $\\exp(n^{1/2})$. In a similar way, the distribution of the largest partial quotients is also studied.", "revisions": [ { "version": "v1", "updated": "2014-05-19T14:37:19.000Z", "abstract": "We investigate from multifractal analysis point of view the increasing rate of the sum of partial quotients $S_n(x)=\\sum_{j=1}^n a_j(x)$, where $x=[a_1(x), a_2(x), \\cdots ]$ is the continued fraction expansion of an irrational $x\\in (0,1)$. Precisely, for an increasing function $\\varphi: \\mathbb{N} \\rightarrow \\mathbb{N}$, one is interested in the Hausdorff dimension of the sets \\[ E_\\varphi = \\left\\{x\\in (0,1): \\lim_{n\\to\\infty} \\frac {S_n(x)} {\\varphi(n)} =1\\right\\}. \\] Several cases are solved by Iommi and Jordan, Wu and Xu, and Xu. We attack the remaining subexponential case $\\exp(n^\\beta), \\ \\beta \\in [1/2, 1)$. We show that when $\\beta \\in [1/2, 1)$, $E_\\varphi$ has Hausdorff dimension $1/2$. Thus surprisingly the dimension has a jump from $1$ to $1/2$ at the increasing rate $\\exp(n^{1/2})$. In a similar way, the distribution of the largest partial quotients is also studied.", "comment": "10 pages", "journal": null, "doi": null }, { "version": "v2", "updated": "2015-10-28T16:38:47.000Z" } ], "analyses": { "keywords": [ "continued fraction expansion", "subexponentially increasing sum", "hausdorff dimension", "multifractal analysis point", "increasing rate" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1405.4747L" } } }