English

The one-sided kissing number in four dimensions

Metric Geometry 2007-05-23 v5 Combinatorics

Abstract

Let H be a closed half-space of n-dimensional Euclidean space. Suppose S is a unit sphere in H that touches the supporting hyperplane of H. The one-sided kissing number B(n) is the maximal number of unit nonoverlapping spheres in H that can touch S. Clearly, B(2)=4. It was proved that B(3)=9. Recently, K. Bezdek proved that B(4)=18 or 19, and conjectured that B(4)=18. We present a proof of this conjecture.

Keywords

Cite

@article{arxiv.math/0511071,
  title  = {The one-sided kissing number in four dimensions},
  author = {Oleg R. Musin},
  journal= {arXiv preprint arXiv:math/0511071},
  year   = {2007}
}
R2 v1 2026-07-22T17:26:51.381Z