English

On the dimension of certain sets araising in the base two expansion

Dynamical Systems 2026-02-03 v4

Abstract

We show that for the base two expansion x=i=12(d1(x)+d2(x)++di(x)) x=\sum_{i=1}^{\infty}2^{-(d_{1}(x)+d_{2}(x)+\dots+d_{i}(x))} with x(0,1]x\in(0,1] and di(x)Nd_{i}(x)\in\mathbb{N} the set A={xlimidi(x)=}A=\{x|\lim_{i\to\infty}d_{i}(x)=\infty\} has Hausdorff dimension zero, this is opposed to a result on the continued fraction expansion, here AA has Hausdorff dimension 1/21/2, see \cite{[GO]}. Furthermore we construct subsets of B={xlim supidi(x)=}B=\{x|\limsup_{i\to\infty}d_{i}(x)=\infty\} which have Hausdorff dimension one and find a dimension spectrum in set BB.

Keywords

Cite

@article{arxiv.2201.09641,
  title  = {On the dimension of certain sets araising in the base two expansion},
  author = {Jörg Neunhäuserer},
  journal= {arXiv preprint arXiv:2201.09641},
  year   = {2026}
}

Comments

The results will be published in a more general setting in another paper