English

A simultaneous version of Host's equidistribution Theorem

Dynamical Systems 2019-04-30 v1 Classical Analysis and ODEs Number Theory

Abstract

Let μ\mu be a probability measure on R/Z\mathbb{R}/\mathbb{Z} that is ergodic under the ×p\times p map, with positive entropy. In 1995, Host showed that if gcd(m,p)=1\gcd(m,p)=1 then μ\mu almost every point is normal in base mm. In 2001, Lindenstrauss showed that the conclusion holds under the weaker assumption that pp does not divide any power of mm. In 2015, Hochman and Shmerkin showed that this holds in the "correct" generality, i.e. if mm and pp are independent. We prove a simultaneous version of this result: for μ\mu typical xx, if m>pm>p are independent, we show that the orbit of (x,x)(x,x) under (×m,×p)(\times m, \times p) equidistributes for the product of the Lebesgue measure with μ\mu. We also show that if m>n>1m>n>1 and nn is independent of pp as well, then the orbit of (x,x)(x,x) under (×m,×n)(\times m, \times n) equidistributes for the Lebesgue measure.

Keywords

Cite

@article{arxiv.1904.12506,
  title  = {A simultaneous version of Host's equidistribution Theorem},
  author = {Amir Algom},
  journal= {arXiv preprint arXiv:1904.12506},
  year   = {2019}
}
R2 v1 2026-06-23T08:51:56.696Z