English

Rational Points in Translations of The Cantor Set

Number Theory 2024-06-05 v4 Dynamical Systems

Abstract

Given two coprime integers p2p\ge 2 and q3q \ge 3, let Dp[0,1)D_p\subset[0,1) consist of all rational numbers which have a finite pp-ary expansion, and let K(q,A)={i=1diqi:diA iN}, K(q, \mathcal{A})=\bigg\{ \sum_{i=1}^\infty \frac{d_i}{q^i}: d_i\in \mathcal{A}~ \forall i\in\mathbb{N} \bigg\}, where A{0,1,,q1}\mathcal{A} \subset \{0,1,\ldots, q-1\} with cardinality 1<#A<q1<\#\mathcal{A}< q. In 2021 Schleischitz showed that #(DpK(q,A))<+\#(D_p\cap K(q,\mathcal{A}))<+\infty. In this paper we show that for any rQr\in\mathbb{Q} and for any αR\alpha\in\mathbb{R}, #((rDp+α)K(q,A))<+. \#\big((r D_p+\alpha)\cap K(q,\mathcal{A})\big)<+\infty.

Keywords

Cite

@article{arxiv.2204.04624,
  title  = {Rational Points in Translations of The Cantor Set},
  author = {Kan Jiang and Derong Kong and Wenxia Li and Zhiqiang Wang},
  journal= {arXiv preprint arXiv:2204.04624},
  year   = {2024}
}

Comments

8 pages, final version