English

Classification of crescent configurations

Combinatorics 2019-01-14 v2

Abstract

Let nn points be in crescent configurations in Rd\mathbb{R}^d if they lie in general position in Rd\mathbb{R}^d and determine n1n-1 distinct distances, such that for every 1in11 \leq i \leq n-1 there is a distance that occurs exactly ii times. Since Erd\H{o}s' conjecture in 1989 on the existence of NN sufficiently large such that no crescent configurations exist on NN or more points, he, Pomerance, and Pal\'asti have given constructions for nn up to 88 but nothing is yet known for n9n \geq 9. Most recently, Burt et. al. had proven that a crescent configuration on nn points exists in Rn2\mathbb{R}^{n-2} for n3n \geq 3. In this paper, we study the classification of these configurations on 44 and 55 points through graph isomorphism and rigidity. Our techniques, which can be generalized to higher dimensions, offer a new viewpoint on the problem through the lens of distance geometry and provide a systematic way to construct crescent configurations.

Keywords

Cite

@article{arxiv.1610.07836,
  title  = {Classification of crescent configurations},
  author = {Rebecca F. Durst and Max Hlavacek and Chi Huynh and Steven J. Miller and Eyvindur A. Palsson},
  journal= {arXiv preprint arXiv:1610.07836},
  year   = {2019}
}

Comments

23 pages; limitations of our methods are clarified and theorems made clearer

R2 v1 2026-06-22T16:30:53.770Z