English

Bad is null

Number Theory 2023-07-20 v1 Dynamical Systems

Abstract

In this paper we develop a general framework of badly approximable points in a metric space XX equipped with a σ\sigma-finite doubling Borel regular measure μ\mu. We establish that under mild assumptions the μ\mu-measure of the set of badly approximable points is always zero. The framework can be applied to a variety of settings in Diophantine approximation and dynamical systems, which we also consider, including weighted and SS-arithmetic Diophantine approximations, Diophantine approximation on manifolds and intrinsic approximations on fractals.

Keywords

Cite

@article{arxiv.2307.10109,
  title  = {Bad is null},
  author = {Victor Beresnevich and Shreyasi Datta and Anish Ghosh and Benjamin Ward},
  journal= {arXiv preprint arXiv:2307.10109},
  year   = {2023}
}
R2 v1 2026-06-28T11:34:51.409Z