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arXiv · 2412.03479

Small kissing polytopes

Antoine Deza·Zhongyuan Liu·Lionel Pournin
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Abstract

A lattice $(d,k)$-polytope is the convex hull of a set of points in $\mathbb{R}^d$ whose coordinates are integers ranging between $0$ and $k$. We consider the smallest possible distance $\varepsilon(d,k)$ between two disjoint lattice $(d,k)$-polytopes. We propose an algebraic model for this distance and derive from it an explicit formula for $\varepsilon(2,k)$. Our model also allows for the computation of previously intractable values of $\varepsilon(d,k)$. In particular, we compute $\varepsilon(3,k)$ when $4\leq{k}\leq8$, $\varepsilon(4,k)$ when $2\leq{k}\leq3$, and $\varepsilon(6,1)$.

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Antoine Deza, Zhongyuan Liu, Lionel Pournin. 2024-12-04. Small kissing polytopes. https://doi.org/10.1007/s10013-025-00742-1

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