A cap covering theorem

Abstract

A cap of spherical radius $\alpha$ on a unit $d$-sphere $S$ is the set of points within spherical distance $\alpha$ from a given point on the sphere. Let $\mathcal{F}$ be a finite set of caps lying on $S$. We prove that if no hyperplane through the center of $S$ divides $\mathcal{F}$ into two non-empty subsets without intersecting any cap in $\mathcal{F}$, then there is a cap of radius equal to the sum of radii of all caps in $\mathcal{F}$ covering all caps of $\mathcal{F}$ provided that the sum of radii is less $\pi /2$. This is the spherical analog of the so-called Circle Covering Theorem by Goodman and Goodman and the strengthening of Fejes Tóth's zone conjecture proved by Jiang and the author arXiv:1703.10550.

6 pages, 2 figures. Combinatorica, accepted. Key words: Bang's plank theorem, coverings

References in corpus (1)

• Proof of László Fejes Tóth's zone conjecture

Cited by in corpus (1)

• Extensions of polynomial plank covering theorems