English

Non-central sections of the regular n-simplex

Functional Analysis 2025-01-28 v2 Combinatorics

Abstract

We show that the maximal non-central hyperplane sections of the regular n-simplex of side-length sqrt 2 at a fixed distance t to the centroid are those parallel to a face of the simplex, if (n2)/(3(n+1))<t<(n1)/(2(n+1))\sqrt{(n-2)/(3(n+1))} < t < \sqrt{(n-1)/(2(n+1))} and n>4n>4. For n=4n=4, the same is true in a slightly smaller range for t. This adds to a previous result for (n1)/(2(n+1))<t<n/(n+1)\sqrt{(n-1)/(2(n+1))} < t < \sqrt{n/(n+1)}. For n=2,3n=2,3, we determine the maximal and the minimal sections for all distances t to the centroid.

Keywords

Cite

@article{arxiv.2312.01325,
  title  = {Non-central sections of the regular n-simplex},
  author = {Hermann König},
  journal= {arXiv preprint arXiv:2312.01325},
  year   = {2025}
}
R2 v1 2026-06-28T13:39:29.536Z