English

A characterization of bad approximability

Number Theory 2018-12-19 v3

Abstract

We show that badly approximable vectors are exactly those that cannot, for any inhomogeneous parameter, be inhomogeneously approximated at every monotone divergent rate. This implies in particular that Kurzweil's Theorem cannot be restricted to any points in the inhomogeneous part. Our results generalize to weighted approximations, and to higher irrationality exponents.

Keywords

Cite

@article{arxiv.1707.00771,
  title  = {A characterization of bad approximability},
  author = {Felipe A. Ramírez},
  journal= {arXiv preprint arXiv:1707.00771},
  year   = {2018}
}

Comments

19 pages; v2: minor changes, not of a mathematical nature; v3: minor changes, not mathematical

R2 v1 2026-06-22T20:36:58.623Z