{ "id": "1805.04744", "version": "v1", "published": "2018-05-12T15:58:49.000Z", "updated": "2018-05-12T15:58:49.000Z", "title": "Level sets of the run-length function of beta-expansions", "authors": [ "Lixuan Zheng" ], "comment": "25 pages, 6 theorems", "categories": [ "math.DS" ], "abstract": "For any $\\beta > 1$, denoted by $r_n(x,\\beta)$ the maximal length of consecutive zeros amongst the first $n$ digits of the $\\beta$-expansion of $x\\in[0,1)$. Let $0\\leq a\\leq b\\leq 1$. The Hausdorff dimension of the level set $$E_{a,b}=\\left\\{x \\in [0,1): \\liminf_{n\\rightarrow \\infty}\\frac{r_n(x,\\beta)}{n}=a,\\ \\limsup_{n\\rightarrow \\infty}\\frac{r_n(x,\\beta)}{n}=b\\right\\}$$ is obtained. As a consequence, the set $$E_a=\\left\\{x \\in [0,1):\\liminf_{n\\rightarrow \\infty}\\frac{r_n(x,\\beta)}{n}=a\\right\\}$$ has Hausdorff dimension ${(1-2a)}^2$ when $0\\leq a\\leq\\frac{1}{2}$. We show that the extremely divergent set $E_{0,1}$ which is of zero Hausdorff dimension is, however, residual which means that it is large from the topological viewpoint. The same problems in the parameter space are also examined.", "revisions": [ { "version": "v1", "updated": "2018-05-12T15:58:49.000Z" } ], "analyses": { "subjects": [ "11K55", "28A80" ], "keywords": [ "level set", "run-length function", "beta-expansions", "zero hausdorff dimension", "maximal length" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable" } } }