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| Content Provider | Springer Nature Link |
|---|---|
| Author | Szirmai, Jenő |
| Copyright Year | 2013 |
| Abstract | The ball (or sphere) packing problem with equal balls, without any symmetry assumption, in a $$3$$ -dimensional space of constant curvature was settled by Böröczky and Florian for the hyperbolic space $$\mathbf H ^3$$ , and, with the proof of the famous Kepler conjecture, by Hales for the Euclidean space $$\mathbf E ^3$$ . The goal of this paper is to extend the problem of finding the densest geodesic ball (or sphere) packing for the other $$3$$ -dimensional homogeneous geometries (Thurston geometries) $$\mathbf S ^2\!\times \!\mathbf R , \mathbf H ^2\!\times \!\mathbf R , $$ $$\widetilde{\mathbf{S \mathbf L _2\mathbf R }}, \mathbf {Nil} , \mathbf {Sol} . $$ In the following a transitive symmetry group of the ball packing is assumed, which is one of the discrete isometry groups of the considered space. Moreover, we describe a candidate of the densest geodesic ball packing. The greatest density until now is $$\approx 0.85327613$$ that is not realized by a packing with equal balls of the hyperbolic space $$\mathbf H ^3$$ . However, that is attained, e.g., by a horoball packing of $$\overline{\mathbf{H }}^3$$ where the ideal centres of horoballs lie on the absolute figure of $$\overline{\mathbf{H }}^3$$ inducing the regular ideal simplex tiling $$(3,3,6)$$ by its Coxeter–Schläfli symbol. In this work we present a geodesic ball packing in the $$\mathbf S ^2\times \mathbf R $$ geometry whose density is $${\approx }0.87757183$$ . The extremal configuration is described in Theorem 2.6. A conjecture for the densest ball packing in Thurston geometries and further remarks are summarized in Sect. 1.1, 1.2 and 2.3. |
| Starting Page | 441 |
| Ending Page | 452 |
| Page Count | 12 |
| File Format | |
| ISSN | 01384821 |
| Journal | Beiträge zur Algebra und Geometrie / Contributions to Algebra and Geometry |
| Volume Number | 55 |
| Issue Number | 2 |
| e-ISSN | 21910383 |
| Language | English |
| Publisher | Springer Berlin Heidelberg |
| Publisher Date | 2013-07-17 |
| Publisher Place | Berlin, Heidelberg |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Thurston geometries Ball packings Density The densest ball packing Packing and covering in $n$ dimensions Tilings in $n$ dimensions Non-Euclidean differential geometry Polyhedra and polytopes; regular figures, division of spaces Algebra Geometry Algebraic Geometry Convex and Discrete Geometry |
| Content Type | Text |
| Resource Type | Article |
| Subject | Algebra and Number Theory Geometry and Topology |
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