English

Thue-Morse constant is not badly approximable

Number Theory 2014-11-06 v2

Abstract

We prove that Thue-Morse constant τTM=0.01101001...2\tau_{TM}=0.01101001..._2 is not a badly approximable number. Moreover, we prove that τTM(a)=0.01101001...a\tau_{TM}(a)=0.01101001..._a is not badly approximable for every integer base a2a\geq 2 such that aa is not divisible by 15. At the same time we provide a precise formula for convergents of the Laurent series f~TM(z)=z1n=1(1z2n)\tilde{f}_{TM}(z) = z^{-1}\prod_{n=1}^\infty (1-z^{-2^n}), thus developing further the research initiated by Alf van der Poorten and others.

Cite

@article{arxiv.1407.3182,
  title  = {Thue-Morse constant is not badly approximable},
  author = {Dzmitry Badziahin and Evgeniy Zorin},
  journal= {arXiv preprint arXiv:1407.3182},
  year   = {2014}
}
R2 v1 2026-06-22T05:02:01.184Z