{ "id": "2208.13855", "version": "v1", "published": "2022-08-29T19:53:09.000Z", "updated": "2022-08-29T19:53:09.000Z", "title": "Determining a Points Configuration on the Line from a Subset of the Pairwise Distances", "authors": [ "Itai Benjamini", "Elad Tzalik" ], "categories": [ "math.MG", "math.CO", "math.PR" ], "abstract": "We consider rigidity type problems on $\\mathbb{R}, S^1$ in a non-generic setting. Given $n$ distinct points $V = \\{ v_1,...,v_n \\}$ and a set of mutual distances $\\mathcal{P} \\subseteq { V \\choose 2}$, does $\\mathcal{P}$ defines the position of $V$ uniquely up to isometry? We show that if $|\\mathcal{P}| =\\Omega(n^{3/2})$, one can determine the position of a subset $V' \\subseteq V$, $|V'| = \\Omega(\\frac{|\\mathcal{P}|}{n})$. The main ingredient in the proof is showing that dense graphs $G=(V,E)$ for which every two non-adjacent vertices have only a few common neighbours must have large cliques. We also consider random distance set $\\mathcal{P}$. If the distance of each pair of points is known with probability $p = \\frac{C \\ln(n)}{n}$ for large enough $C$ then it is possible to reconstruct $V$ from the distances w.h.p. and provide a randomized algorithm with linear expected running time that returns an embedding to the line w.h.p.", "revisions": [ { "version": "v1", "updated": "2022-08-29T19:53:09.000Z" } ], "analyses": { "keywords": [ "points configuration", "pairwise distances", "rigidity type problems", "random distance set", "determining" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }