English

Is it possible to determine a point lying in a simplex if we know the distances from the vertices?

Metric Geometry 2016-04-05 v2 Functional Analysis

Abstract

It is an elementary fact that if we fix an arbitrary set of d+1d+1 affine independent points {p0,pd}\{p_0,\dots p_d\} in Rd\mathbb{R}^d, then the Euclidean distances {xpj}j=0d\{|x-p_j|\}_{j=0}^d determine the point xx in Rd\mathbb{R}^d uniquely. In this paper we investigate a similar problem in general normed spaces which is motivated by this known fact. Namely, we characterize those, at least dd-dimensional, real normed spaces (X,)(X, \|\cdot\|) such that for every set of d+1d+1 affine independent points {p0,pd}X\{p_0,\dots p_d\} \subset X, the distances {xpj}j=0d\{\|x-p_j\|\}_{j=0}^d determines the point xx lying in the simplex Conv(p0,pd)\mathrm{Conv}(p_0,\dots p_d) uniquely. Surprisingly, the characterization depends on dd.

Keywords

Cite

@article{arxiv.1507.05114,
  title  = {Is it possible to determine a point lying in a simplex if we know the distances from the vertices?},
  author = {György Pál Gehér},
  journal= {arXiv preprint arXiv:1507.05114},
  year   = {2016}
}

Comments

14 pages, 3 figures The first Arxiv version had a different title!