English

Low Discrepancy Digital Kronecker-Van der Corput Sequences

Number Theory 2024-09-10 v1

Abstract

The discrepancy of a sequence measures how quickly it approaches a uniform distribution. Given a natural number dd, any collection of one-dimensional so-called low discrepancy sequences {Si:1id}\left\{S_i:1\le i \le d\right\} can be concatenated to create a dd-dimensional hybrid sequence\textit{hybrid sequence} (S1,,Sd)(S_1,\dots,S_d). Since their introduction by Spanier in 1995, many connections between the discrepancy of a hybrid sequence and the discrepancy of its component sequences have been discovered. However, a proof that a hybrid sequence is capable of being low discrepancy has remained elusive. This paper remedies this by providing an explicit connection between Diophantine approximation over function fields and two dimensional low discrepancy hybrid sequences. Specifically, let Fq\mathbb{F}_q be the finite field of cardinality qq. It is shown that some real numbered hybrid sequence H(Θ(t),P(t)):=H(Θ,P)\mathbf{H}(\Theta(t),P(t)):=\textbf{H}(\Theta,P) built from the digital Kronecker sequence associated to a Laurent series Θ(t)Fq((t1))\Theta(t)\in\mathbb{F}_q((t^{-1})) and the digital Van der Corput sequence associated to an irreducible polynomial P(t)Fq[t]P(t)\in\mathbb{F}_q[t] meets the above property. More precisely, if Θ(t)\Theta(t) is a counterexample to the so called tt-adic Littlewood Conjecture\textit{-adic Littlewood Conjecture} (tt-LCLC), then another Laurent series Φ(t)Fq((t1))\Phi(t)\in\mathbb{F}_q((t^{-1})) induced from Θ(t)\Theta(t) and P(t)P(t) can be constructed so that H(Φ,P)\mathbf{H}(\Phi,P) is low discrepancy. Such counterexamples to tt-LCLC are known over a number of finite fields by, on the one hand, Adiceam, Nesharim and Lunnon, and on the other, by Garrett and the author.

Keywords

Cite

@article{arxiv.2409.05469,
  title  = {Low Discrepancy Digital Kronecker-Van der Corput Sequences},
  author = {Steven Robertson},
  journal= {arXiv preprint arXiv:2409.05469},
  year   = {2024}
}

Comments

13 pages, 1 figure

R2 v1 2026-06-28T18:38:18.541Z