English

Diophantine approximations on fractals

Dynamical Systems 2011-01-21 v2 Number Theory

Abstract

We exploit dynamical properties of diagonal actions to derive results in Diophantine approximations. In particular, we prove that the continued fraction expansion of almost any point on the middle third Cantor set (with respect to the natural measure) contains all finite patterns (hence is well approximable). Similarly, we show that for a variety of fractals in [0,1]^2, possessing some symmetry, almost any point is not Dirichlet improvable (hence is well approximable) and has property C (after Cassels). We then settle by similar methods a conjecture of M. Boshernitzan saying that there are no irrational numbers x in the unit interval such that the continued fraction expansions of {nx mod1 : n is a natural number} are uniformly eventually bounded.

Keywords

Cite

@article{arxiv.0908.2350,
  title  = {Diophantine approximations on fractals},
  author = {Manfred Einsiedler and Lior Fishman and Uri Shapira},
  journal= {arXiv preprint arXiv:0908.2350},
  year   = {2011}
}

Comments

Final version, to appear in GAFA

R2 v1 2026-06-21T13:36:04.269Z