English

The Duffin-Schaeffer Conjecture with extra divergence

Number Theory 2009-03-20 v3

Abstract

Given a nonnegative function ψ:NR\psi : \N \to \R , let W(ψ)W(\psi) denote the set of real numbers xx such that nxa<ψ(n)|nx -a| < \psi(n) for infinitely many reduced rationals a/n(n>0)a/n (n>0) . A consequence of our main result is that W(ψ)W(\psi) is of full Lebesgue measure if there exists an ϵ>0\epsilon > 0 such that nN(ψ(n)n)1+ϵφ(n)=. \textstyle \sum_{n\in\N}(\frac{\psi(n)}{n})^{1+\epsilon}\varphi (n)=\infty . The Duffin-Schaeffer Conjecture is the corresponding statement with ϵ=0\epsilon = 0 and represents a fundamental unsolved problem in metric number theory. Another consequence is that W(ψ)W(\psi) is of full Hausdorff dimension if the above sum with ϵ=0\epsilon = 0 diverges; i.e. the dimension analogue of the Duffin-Schaeffer Conjecture is true.

Keywords

Cite

@article{arxiv.0811.1234,
  title  = {The Duffin-Schaeffer Conjecture with extra divergence},
  author = {Alan Haynes and Andrew Pollington and Sanju Velani},
  journal= {arXiv preprint arXiv:0811.1234},
  year   = {2009}
}

Comments

13 pages -- a stronger theorem than in the original version is proved and connections to the work of Harman are made. Also the proof of the main theorem is split into two natural steps -- hopefully making it easier to see the overall strategy

R2 v1 2026-06-21T11:39:27.560Z