English

Non-Salem sets in multiplicative Diophantine approximation

Number Theory 2024-09-20 v1

Abstract

In this paper, we answer a question of Cai-Hambrook in (arXiv ⁣:\colon 2403.19410). Furthermore, we compute the Fourier dimension of the multiplicative ψ\psi-well approximable set M2×(ψ)={(x1,x2)[0,1]2 ⁣:qx1qx2<ψ(q) for infinitely many qN},M_2^{\times}(\psi)=\left\{(x_1,x_2)\in [0,1]^{2}\colon \|qx_1\|\|qx_2\|<\psi(q) \text{ for infinitely many } q\in \N\right\}, where ψ ⁣:N[0,14)\psi\colon\N\to [0,\frac{1}{4}) is a positive function satisfying qψ(q)log1ψ(q)<.\sum_q\psi(q)\log\frac{1}{\psi(q)}<\infty. As a corollary, we show that the set M2×(qqτ)M_2^{\times}(q\mapsto q^{-\tau}) is non-Salem for τ>1.\tau>1.

Cite

@article{arxiv.2409.12557,
  title  = {Non-Salem sets in multiplicative Diophantine approximation},
  author = {Bo Tan and Qing-Long Zhou},
  journal= {arXiv preprint arXiv:2409.12557},
  year   = {2024}
}

Comments

15 pages

R2 v1 2026-06-28T18:49:56.413Z