English

Permutations of point sets in $\mathbb{R}^d$

Combinatorics 2023-04-05 v2 Metric Geometry

Abstract

Given a set SS consisting of nn points in Rd\mathbb{R}^d and one or two vantage points, we study the number of orderings of SS induced by measuring the distance (for one vantage point) or the average distance (for two vantage points) from the vantage point(s) to the points of SS as the vantage points move through Rd.\mathbb{R}^d. With one vantage point, a theorem of Good and Tideman \cite{MR505547} shows the maximum number of orderings is a sum of unsigned Stirling numbers of the first kind. We show that the minimum value in all dimensions is 2n2,2n-2, achieved by nn equally spaced points on a line. We investigate special configurations that achieve intermediate numbers of orderings in the one--dimensional and two--dimensional cases. We also treat the case when the points are on the sphere S2,S^2, connecting spherical and planar configurations. We briefly consider an application using weights suggested by an application to social choice theory. We conclude with several open problems that we believe deserve further study.

Keywords

Cite

@article{arxiv.2106.14140,
  title  = {Permutations of point sets in $\mathbb{R}^d$},
  author = {Alvaro Carbonero and Beth Anne Castellano and Gary Gordon and Charles Kulick and Brittany Ohlinger and Karie Schmitz},
  journal= {arXiv preprint arXiv:2106.14140},
  year   = {2023}
}

Comments

29 pages, 11 figures

R2 v1 2026-06-24T03:38:04.114Z