The Stützfunktion and the Cut Function

Abstract

I review some standard theory of convex bodies in $\mathbb{R}^3$ and rephrase it in a formalism of Ted Newman to show the relation between the Stützfunktion of the former theory and the cut function introduced by Ted. This leads to a conjectured inequality for space-like two-spheres in Minkowski space that generalises Minkowski's inequality and is implied by Penrose's cosmic censorship hypothesis.

10 pages. This is a corrected, revised and updated version of a paper which originally appeared in Recent Advances in General Relativity, eds. A I Janis and J R Porter, Einstein Studies vol. 4, Birkhaüser 1992