Counterintuitive patterns on angles and distances between lattice points in high dimensional hypercubes

Abstract

Let $\mathcal{S}$ be a finite set of integer points in ${\mathbb{R}}^d$, which we assume has many symmetries, and let $P\in {\mathbb{R}}^d$ be a fixed point. We calculate the distances from $P$ to the points in $\mathcal{S}$ and compare the results. In some of the most common cases, we find that they lead to unexpected conclusions if the dimension is sufficiently large. For example, if $\mathcal{S}$ is the set of vertices of a hypercube in ${\mathbb{R}}^d$ and $P$ is any point inside, then almost all triangles $PAB$ with $A,B\in \mathcal{S}$ are almost equilateral. Or, if $P$ is close to the center of the cube, then almost all triangles $PAB$ with $A\in \mathcal{S}$ and $B$ anywhere in the hypercube are almost right triangles.

16 pages, 1 figure