English

Sets in $\mathbb{R}^d$ determining $k$ taxicab distances

Combinatorics 2020-07-15 v3 Metric Geometry

Abstract

We address an analog of a problem introduced by Erd\H{o}s and Fishburn, itself an inverse formulation of the famous Erd\H{o}s distance problem, in which the usual Euclidean distance is replaced with the metric induced by the 1\ell^1-norm, commonly referred to as the taxicab metric\textit{taxicab metric}. Specifically, we investigate the following question: given d,kNd,k\in \mathbb{N}, what is the maximum size of a subset of Rd\mathbb{R}^d that determines at most kk distinct taxicab distances, and can all such optimal arrangements be classified? We completely resolve the question in dimension d=2d=2, as well as the k=1k=1 case in dimension d=3d=3, and we also provide a full resolution in the general case under an additional hypothesis.

Keywords

Cite

@article{arxiv.1911.08067,
  title  = {Sets in $\mathbb{R}^d$ determining $k$ taxicab distances},
  author = {Vajresh Balaji and Olivia Edwards and Anne Marie Loftin and Solomon Mcharo and Lo Phillips and Alex Rice and Bineyam Tsegaye},
  journal= {arXiv preprint arXiv:1911.08067},
  year   = {2020}
}

Comments

16 pages, 1 figure with 2 images, 1 table. Typos corrected, sections 5 and 6 revised to be more detailed, structured, and readable. Version to appear in Involve, a Journal of Mathematics

R2 v1 2026-06-23T12:20:12.700Z