Analysis of the Jante’s Law Process and Proof of Conjecture: Coupling Y (⋅) and Z(⋅)

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11 Sept 2024

Authors:

(1) Edward Crane, School of Mathematics, University of Bristol, BS8 1TH, UK;

(2) Stanislav Volkov, Centre for Mathematical Sciences, Lund University, Box 118 SE-22100, Lund, Sweden.

Abstract and Introduction

Preliminaries

Reduction to the case of uniform geometry

All original points are eventually removed, a. s.

Proof of Theorem 1

Coupling Y (⋅) and Z(⋅)

Acknowledgements and References

Appendix

6 Coupling Y (⋅) and Z(⋅)

In this section, we complete the proof of Theorem 2. By Lemma 10 it suffices to prove the absolute continuity of the limit point ξ for a B-valued Jante’s law process where B is bounded. So we shall assume throughout this section that B is bounded, and therefore has uniform geometry.

We will need an isoperimetric inequality for inner shells of convex bodies, for which we have been unable to find a reference. It concerns the following problem. Suppose you have a (possibly) hollow chocolate egg whose outer boundary is the boundary of a convex body. If all the chocolate is within distance r of the outer boundary of the egg, what is the maximum quantity of chocolate that can possibly be contained within a ball of radius R? See Figure 4.

Figure 4: Lemma 16 bounds the quantity of chocolate in the ball of radius R.

Figure 5: The supporting hyperplane at z to the green convex body B cuts at least one axisparallel line through x within distance √d∥z − x∥ of x.

This paper is available on arxiv under CC 4.0 license.


8 Think of δ small and ∆ large.