{ "id": "1806.06166", "version": "v1", "published": "2018-06-16T01:38:27.000Z", "updated": "2018-06-16T01:38:27.000Z", "title": "$α$-expansions with odd partial quotients", "authors": [ "Florin P. Boca", "Claire Merriman" ], "comment": "13 pages", "categories": [ "math.DS" ], "abstract": "We consider an analogue of Nakada's $\\alpha$-continued fraction transformations in the setting of continued fractions with odd partial quotients. More precisely, given $\\alpha \\in [\\frac{1}{2}(\\sqrt{5}-1),\\frac{1}{2}(\\sqrt{5}+1)]$, we show that every irrational number $x\\in [\\alpha-2,\\alpha)$ can be uniquely represented as $ x=\\frac{e_1}{d_1+\\frac{e_2}{d_2+\\frac{e_3}{d_3+\\cdots}}} $, with $e_i =e_i(x;\\alpha) \\in \\{ \\pm 1\\}$ and $d_i =d_i(x;\\alpha) \\in 2{\\mathbb N} -1$ determined by the iterates of the transformation $\\varphi_\\alpha (x) := \\frac{1}{| x|} - 2 \\left[ \\frac{1}{2| x|} +\\frac{1-\\alpha}{2} \\right]-1$ of $[\\alpha -2,\\alpha)$. We also describe the natural extension of $\\varphi_\\alpha$ and prove that the endomorphism $\\varphi_\\alpha$ is exact.", "revisions": [ { "version": "v1", "updated": "2018-06-16T01:38:27.000Z" } ], "analyses": { "subjects": [ "37E05", "11J70", "11K50", "37A35" ], "keywords": [ "odd partial quotients", "expansions", "continued fraction transformations", "natural extension", "irrational number" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }