{ "id": "1803.07338", "version": "v1", "published": "2018-03-20T09:52:19.000Z", "updated": "2018-03-20T09:52:19.000Z", "title": "The $β$-transformation with a hole at 0", "authors": [ "Charlene Kalle", "Derong Kong", "Niels Langeveld", "Wenxia Li" ], "comment": "32 pages, 4 figures", "categories": [ "math.DS" ], "abstract": "For $\\beta\\in(1,2]$ the $\\beta$-transformation $T_\\beta: [0,1) \\to [0,1)$ is defined by $T_\\beta ( x) = \\beta x \\pmod 1$. For $t\\in[0, 1)$ let $K_\\beta(t)$ be the survivor set of $T_\\beta$ with hole $(0,t)$ given by \\[K_\\beta(t):=\\{x\\in[0, 1): T_\\beta^n(x)\\not \\in (0, t) \\textrm{ for all }n\\ge 0\\}.\\] In this paper we characterise the bifurcation set $E_\\beta$ of all parameters $t\\in[0,1)$ for which the set valued function $t\\mapsto K_\\beta(t)$ is not locally constant. We show that $E_\\beta$ is a Lebesgue null set of full Hausdorff dimension for all $\\beta\\in(1,2)$. We prove that for Lebesgue almost every $\\beta\\in(1,2)$ the bifurcation set $E_\\beta$ contains both infinitely many isolated and accumulation points arbitrarily close to zero. On the other hand, we show that the set of $\\beta\\in(1,2)$ for which $E_\\beta$ contains no isolated points has zero Hausdorff dimension. These results contrast with the situation for $E_2$, the bifurcation set of the doubling map. Finally, we give for each $\\beta \\in (1,2)$ a lower and upper bound for the value $\\tau_\\beta$, such that the Hausdorff dimension of $K_\\beta(t)$ is positive if and only if $t< \\tau_\\beta$. We show that $\\tau_\\beta \\le 1-\\frac1{\\beta}$ for all $\\beta \\in (1,2)$.", "revisions": [ { "version": "v1", "updated": "2018-03-20T09:52:19.000Z" } ], "analyses": { "subjects": [ "11K55", "11A63", "68R15", "26A30", "28D05", "37B10", "37E05", "37E15" ], "keywords": [ "bifurcation set", "transformation", "zero hausdorff dimension", "accumulation points arbitrarily close", "full hausdorff dimension" ], "note": { "typesetting": "TeX", "pages": 32, "language": "en", "license": "arXiv", "status": "editable" } } }