English

Arithmetical properties of real numbers related to beta-expansions

Number Theory 2017-08-11 v1

Abstract

The main purpose of this paper is to study the arithmetical properties of values m=0βw(m)\sum_{m=0}^{\infty} \beta^{-w(m)}, where β\beta is a fixed Pisot or Salem number and w(m)w(m) (m=0,1,m=0,1,\ldots) are distinct sequences of nonnegative integers with w(m+1)>w(m)w(m+1)>w(m) for any sufficiently large mm. We first introduce criteria for the algebraic independence of such values. Our criteria are applicable to certain sequences w(m)w(m) (m=0,1,m=0,1,\ldots) with limmw(m+1)/w(m)=1.\lim_{m\to\infty}w(m+1)/w(m)=1. For example, we prove that two numbers m=1βφ(1,0;m),m=3βφ(0,1;m)\sum_{m=1}^{\infty}\beta^{-\lfloor \varphi(1,0;m)\rfloor}, \sum_{m=3}^{\infty}\beta^{-\lfloor \varphi(0,1;m)\rfloor} are algebraically independent, where φ(1,0;m)=mlogm\varphi(1,0;m)=m^{\log m} and φ(0,1;m)=mloglogm\varphi(0,1;m)=m^{\log\log m}. \par Moreover, we also give criteria for linear independence of real numbers. Our criteria are applicable to the values m=0βmρ\sum_{m=0}^{\infty}\beta^{-\lfloor m^\rho\rfloor}, where β\beta is a Pisot or Salem number and ρ\rho is a real number greater than 1.

Keywords

Cite

@article{arxiv.1708.03093,
  title  = {Arithmetical properties of real numbers related to beta-expansions},
  author = {Hajime Kaneko},
  journal= {arXiv preprint arXiv:1708.03093},
  year   = {2017}
}

Comments

34 pages