Saved in:
Bibliographic Details
Main Authors: Bugeaud, Yann, Kaneko, Hajime, Kim, Dong Han
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.17177
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911531170529280
author Bugeaud, Yann
Kaneko, Hajime
Kim, Dong Han
author_facet Bugeaud, Yann
Kaneko, Hajime
Kim, Dong Han
contents Let $ξ$ be a real number and $b \ge 2$ an integer. We study the relationship between the irrationality exponent of $ξ$ and the subword complexity $p(n, \mathbf{x})$ of the $b$-ary expansion $\mathbf{x}$ of $ξ$, where $p(n, \mathbf{x})$ counts the number of distinct blocks of length $n$ in $\mathbf{x}$, for $n \ge 1$. If the irrationality exponent of $ξ$ is equal to $2$, which is the case for almost all real numbers $ξ$, we show that the limit superior of the sequence $(p(n, \mathbf{x}) / n)_{n \ge 1}$ is at least equal to 4/3. The proof is based on a careful study of the evolution of the Rauzy graphs of infinite words of low complexity.
format Preprint
id arxiv_https___arxiv_org_abs_2510_17177
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the irrationality exponent of real numbers with low complexity expansion
Bugeaud, Yann
Kaneko, Hajime
Kim, Dong Han
Number Theory
Combinatorics
Dynamical Systems
11A63, 11J82 (primary), 68R15 (secondary)
Let $ξ$ be a real number and $b \ge 2$ an integer. We study the relationship between the irrationality exponent of $ξ$ and the subword complexity $p(n, \mathbf{x})$ of the $b$-ary expansion $\mathbf{x}$ of $ξ$, where $p(n, \mathbf{x})$ counts the number of distinct blocks of length $n$ in $\mathbf{x}$, for $n \ge 1$. If the irrationality exponent of $ξ$ is equal to $2$, which is the case for almost all real numbers $ξ$, we show that the limit superior of the sequence $(p(n, \mathbf{x}) / n)_{n \ge 1}$ is at least equal to 4/3. The proof is based on a careful study of the evolution of the Rauzy graphs of infinite words of low complexity.
title On the irrationality exponent of real numbers with low complexity expansion
topic Number Theory
Combinatorics
Dynamical Systems
11A63, 11J82 (primary), 68R15 (secondary)
url https://arxiv.org/abs/2510.17177