{ "id": "1907.13031", "version": "v1", "published": "2019-07-30T15:44:49.000Z", "updated": "2019-07-30T15:44:49.000Z", "title": "Dimension theory of Diophantine approximation related to $β$-transformations", "authors": [ "Wanlou WU", "Lixuan Zheng" ], "categories": [ "math.DS" ], "abstract": "Let $T_\\beta$ be the $\\beta$-transformation on $[0,1)$ defined by $$T_\\beta(x)=\\beta x\\text{ mod }1.$$ We study the Diophantine approximation of the orbit of a point $x$ under $T_\\beta$. Precisely, for given two positive functions $\\psi_1,~\\psi_2:\\mathbb{N}\\rightarrow\\mathbb{R}^+$, define $$\\mathcal{L}(\\psi_1):=\\left\\{x\\in[0,1]:T_\\beta^n x<\\psi_1(n),\\text{ for infinitely many $n\\in\\mathbb{N}$}\\right\\},$$ $$\\mathcal{U}(\\psi_2):=\\left\\{x\\in [0,1]:\\forall~N\\gg1,~\\exists~n\\in[0,N],~s.t.~T^n_\\beta x<\\psi_2(N)\\right\\},$$ where $\\gg$ means large enough. We compute the Hausdorff dimension of the set $\\mathcal{L}(\\psi_1)\\cap\\mathcal{U}(\\psi_2)$. As a corollary, we estimate the Hausdorff dimension of the set $\\mathcal{U}(\\psi_2)$.", "revisions": [ { "version": "v1", "updated": "2019-07-30T15:44:49.000Z" } ], "analyses": { "keywords": [ "diophantine approximation", "dimension theory", "transformation", "hausdorff dimension", "means large" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }