English

$M\backslash L$ is not closed

Number Theory 2020-04-09 v2

Abstract

We show that 1+3/21+3/\sqrt{2} is a point of the Lagrange spectrum LL which is accumulated by a sequence of elements of the complement MLM\setminus L of the Lagrange spectrum in the Markov spectrum MM. In particular, MLM\setminus L is not a closed subset of R\mathbb{R}, so that a question by T. Bousch has a negative answer.

Cite

@article{arxiv.1912.02698,
  title  = {$M\backslash L$ is not closed},
  author = {Davi Lima and Carlos Matheus and Carlos Gustavo Moreira and Sandoel Vieira},
  journal= {arXiv preprint arXiv:1912.02698},
  year   = {2020}
}

Comments

33 pages, to appear in Int. Math. Res. Notices

R2 v1 2026-06-23T12:37:08.720Z