arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1401.6473math.DS
收藏

唯一Beta展开式的豪斯多夫维数

Hausdorff dimension of unique beta expansions

Derong Kong, Wenxia Li

摘要:

给定一个整数$N\ge 2$和一个实数$β>1$,令$Γ_{β,N}$是所有$x=\sum_{i=1}^\infty {d_i}/{β^i}$的集合,其中所有$i\ge 1$具有$d_i\in\{0,1,\cdots,N-1\}$。无限序列$(d_i)$称为$β$ -$x$的扩展。设$\mathbf{U}_{β,N}$是$Γ_{β,N}$中具有唯一$β$展开式的所有$x$的集合.在任意容许区间$[{β}_L,{β}_U]$上,给出了$β$的$\mathbf{U}_{β,N}$的豪斯多夫维数的显式表达式,其中${β_L}$是纯Parry数,${β_U}$是超越数,其准贪婪展开式与经典Thue-Morse序列有关.这使我们能够计算几乎每个$β>1$的$\U{N}$的豪斯多夫维数。特别是,这改进了G{á}bor Kall{ó}s(1999,2001)的主要结果。此外,我们发现,尺寸函数$f(β)=\dim_H\mathbf{U}_{β,N}$频繁波动的$β\in(1,N)$。

英文摘要:

Given an integer $N\ge 2$ and a real number $β>1$, let $Γ_{β,N}$ be the set of all $x=\sum_{i=1}^\infty {d_i}/{β^i}$ with $d_i\in\{0,1,\cdots,N-1\}$ for all $i\ge 1$. The infinite sequence $(d_i)$ is called a $β$-expansion of $x$. Let $\mathbf{U}_{β,N}$ be the set of all $x$'s in $Γ_{β,N}$ which have unique $β$-expansions. We give explicit formula of the Hausdorff dimension of $\mathbf{U}_{β,N}$ for $β$ in any admissible interval $[{β}_L,{β}_U]$, where ${β_L}$ is a purely Parry number while ${β_U}$ is a transcendental number whose quasi-greedy expansion of $1$ is related to the classical Thue-Morse sequence. This allows us to calculate the Hausdorff dimension of $\U{N}$ for almost every $β>1$. In particular, this improves the main results of G{á}bor Kall{ó}s (1999, 2001). Moreover, we find that the dimension function $f(β)=\dim_H\mathbf{U}_{β,N}$ fluctuates frequently for $β\in(1,N)$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑