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Related papers: On the Packing Density Bound in 3-Space

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We define three-point bounds for sphere packing that refine the linear programming bound, and we compute these bounds numerically using semidefinite programming by choosing a truncation radius for the three-point function. As a result, we…

Metric Geometry · Mathematics 2022-07-01 Henry Cohn , David de Laat , Andrew Salmon

We consolidate what is currently known about packing densities of 4-point permutations and in the process improve the lower bounds for the packing densities of 1324 and 1342. We also provide rigorous upper bounds for the packing densities…

Combinatorics · Mathematics 2023-06-22 Jakub Sliacan , Walter Stromquist

This paper provides the currently best known upper bound on the density of a packing in three-dimensional Euclidean space of two types of spheres whose size ratio is the largest one that allows the insertion of a small sphere in each…

Metric Geometry · Mathematics 2025-05-21 Thomas Fernique , Daria Pchelina

We obtain an upper bound to the packing density of regular tetrahedra. The bound is obtained by showing the existence, in any packing of regular tetrahedra, of a set of disjoint spheres centered on tetrahedron edges, so that each sphere is…

Metric Geometry · Mathematics 2010-11-23 Simon Gravel , Veit Elser , Yoav Kallus

We provide, for any $r\in (0,1)$, lower and upper bounds on the maximal density of a packing in the Euclidean plane of discs of radius $1$ and $r$. The lower bounds are mostly folk, but the upper bounds improve the best previously known…

Metric Geometry · Mathematics 2022-06-07 Thomas Fernique

In this paper we determine new upper bounds for the maximal density of translative packings of superballs in three dimensions (unit balls for the $l^p_3$-norm) and of Platonic and Archimedean solids having tetrahedral symmetry. Thereby, we…

Metric Geometry · Mathematics 2017-07-31 Maria Dostert , Cristóbal Guzmán , Fernando Mário de Oliveira Filho , Frank Vallentin

In the early 1990s, A. Bezdek and W. Kuperberg used a relatively simple argument to show a surprising result: The maximum packing density of circular cylinders of infinite length in $\mathbb{R}^3$ is exactly $\pi/\sqrt{12}$, the planar…

Metric Geometry · Mathematics 2017-09-14 Wöden Kusner

This is the fifth in a series of papers giving a proof of the Kepler conjecture, which asserts that the density of a packing of congruent spheres in three dimensions is never greater than $\pi/\sqrt{18}\approx 0.74048...$. This is the…

Metric Geometry · Mathematics 2007-05-23 Thomas C. Hales

In \cite{Sz17-2} we proved that to each saturated congruent hyperball packing exists a decomposition of $3$-dimensional hyperbolic space $\mathbb{H}^3$ into truncated tetrahedra. Therefore, in order to get a density upper bound for…

Metric Geometry · Mathematics 2018-12-18 Jenő Szirmai

We study packing densities for set partitions, which is a generalization of packing words. We use results from the literature about packing densities for permutations and words to provide packing densities for set partitions. These results…

Combinatorics · Mathematics 2015-04-10 Adam M. Goyt , Lara K. Pudwell

In this paper, we study the 3D strip packing problem in which we are given a list of 3-dimensional boxes and required to pack all of them into a 3-dimensional strip with length 1 and width 1 and unlimited height to minimize the height used.…

Data Structures and Algorithms · Computer Science 2007-05-23 Xin Han , Kazuo Iwama , Guochuan Zhang

We improve the previously best known upper bounds on the sizes of $\theta$-spherical codes for every $\theta<\theta^*\approx 62.997^{\circ}$ at least by a factor of $0.4325$, in sufficiently high dimensions. Furthermore, for sphere packing…

Metric Geometry · Mathematics 2023-10-10 Naser T. Sardari , Masoud Zargar

We prove that for all fixed $p > 2$, the translative packing density of unit $\ell_p$-balls in $\mathbb{R}^n$ is at most $2^{(\gamma_p + o(1))n}$ with $\gamma_p < - 1/p$. This is the first exponential improvement in high dimensions since…

Metric Geometry · Mathematics 2020-02-17 Ashwin Sah , Mehtaab Sawhney , David Stoner , Yufei Zhao

In this paper we prove a theorem that provides an upper bound for the density of packings of congruent copies of a given convex body in $\mathbb{R}^n$; this theorem is a generalization of the linear programming bound for sphere packings. We…

Metric Geometry · Mathematics 2019-11-07 Fernando Mário de Oliveira Filho , Frank Vallentin

Suppose one has a collection of disks of various sizes with disjoint interiors, a packing in the plane, and suppose the ratio of the smallest radius divided by the largest radius lies between $1$ and $q$. In his 1964 book Regular Figures…

Metric Geometry · Mathematics 2023-03-21 Robert Connelly , Maurice Pierre

We develop an analogue for sphere packing of the linear programming bounds for error-correcting codes, and use it to prove upper bounds for the density of sphere packings, which are the best bounds known at least for dimensions 4 through…

Metric Geometry · Mathematics 2012-03-15 Henry Cohn , Noam Elkies

In this paper we prove an asymptotic lower bound for the sphere packing density in dimensions divisible by four. This asymptotic lower bound improves on previous asymptotic bounds by a constant factor and improves not just lower bounds for…

Metric Geometry · Mathematics 2011-06-01 Stephanie Vance

We give theorems that can be used to upper bound the densities of packings of different spherical caps in the unit sphere and of translates of different convex bodies in Euclidean space. These theorems extend the linear programming bounds…

Metric Geometry · Mathematics 2014-09-26 David de Laat , Fernando Mario de Oliveira Filho , Frank Vallentin

The packing density of the regular cross-polytope in Euclidean $n$-space is unknown except in dimensions $2$ and $4$ where it is 1. The only non-trivial upper bound is due to Gravel, Elser, and Kallus (2011) who proved that for $n=3$ the…

Metric Geometry · Mathematics 2026-04-09 G. Fejes Tóth , F. Fodor , V. Vígh

In this paper we consider ball packings in $4$-dimensional hyperbolic space. We show that it is possible to exceed the conjectured $4$-dimensional realizable packing density upper bound due to L. Fejes T\'oth (Regular Figures, 1964). We…

Metric Geometry · Mathematics 2014-08-25 Robert Thijs Kozma , Jenő Szirmai
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