Abstract
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-Tóth (Regular Figures, Macmillian, New York, 1964). We give seven examples of horoball packing configurations that yield higher densities of \(0.71644896\dots \), where horoballs are centered at ideal vertices of certain Coxeter simplices, and are invariant under the actions of their respective Coxeter groups.
Similar content being viewed by others
References
Bezdek, K.: Sphere packings revisited. European J. Combin. 27, 864–883 (2006)
Bowen, L., Radin, C.: Densest packing of equal spheres in hyperbolic space. Discrete Comput. Geom. 29, 23–39 (2003)
Böröczky, K.: Packing of spheres in spaces of constant curvature. Acta Math. Acad. Sci. Hungar. 32, 243–261 (1978)
Böröczky, K., Florian, A.: Über die dichteste Kugelpackung im hyperbolischen Raum. Acta Math. Acad. Sci. Hungar. 15, 237–245 (1964)
Fejes Tóth, L.: Regular Figures. Macmillian, New York (1964)
Fejes Tóth, G., Kuperberg, W.: Packing and covering with convex sets. In: Gruber, P.M., Willis, J.M. (eds.) Handbook of Convex Geometry Volume B, pp. 799–860. North-Holland, Amsterdam (1983)
Fejes Tóth, G., Kuperberg, G., Kuperberg, W.: Highly saturated packings and reduced coverings. Monatsh. Math. 125, 127–145 (1998)
Hales, T.C.: Historical overview of the Kepler conjecture. Discrete Comput. Geom. 35, 5–20 (2006)
Jacquemet, M.: The inradius of a hyperbolic truncated \(n\)-simplex. Discrete Comput. Geom. 51, 997–1016 (2014)
Johnson, N.W., Kellerhals, R., Ratcliffe, J.G., Tschants, S.T.: The size of a hyperbolic coxeter simplex. Transform. Groups 4, 329–353 (1999)
Johnson, N.W., Kellerhals, R., Ratcliffe, J.G., Tschants, S.T.: Commensurability classes of hyperbolic Coxeter groups. Linear Algebra Appl. 345, 119–147 (2002)
Johnson, N.W., Weiss, A.I.: Quaternionic modular groups. Linear Algebra Appl. 295, 159–189 (1999)
Kellerhals, R.: The dilogarithm and volumes of hyperbolic polytopes. AMS Math. Surveys Monogr. 37, 301–336 (1991)
Kellerhals, R.: Ball packings in spaces of constant curvature and the simplicial density function. J. Reine Angew. Math. 494, 189–203 (1998)
Kozma, R.T., Szirmai, J.: Optimally dense packings for fully asymptotic Coxeter tilings by horoballs of different types. Monatsh. Math. 168, 27–47 (2012)
Marshall, T.H.: Asymptotic volume formulae and hyperbolic ball packing. Ann. Acad. Sci. Fenn. Math. 24, 31–43 (1999)
Molnár, E.: The Projective Interpretation of the eight 3-dimensional homogeneous geometries. Beitr. Algebra Geom. 38, 261–288 (1997)
Molnár, E., Szirmai, J.: Symmetries in the 8 homogeneous 3-geometries. Symmetry Cult. Sci. 21, 87–117 (2010)
Radin, C.: The symmetry of optimally dense packings. In: Prékopa, A., Molnár, E. (eds.) Non-Eucledian Geometries, pp. 197–207. Springer Verlag, New York (2006)
Rogers, C.A.: Packing and Covering, Cambridge Tracts in Mathematics and Mathematical Physics, vol. 54. Cambridge University Press, Cambridge (1964)
Szirmai, J.: The optimal ball and horoball packings of the Coxeter tilings in the hyperbolic 3-space. Beitr. Algebra Geom. 46, 545–558 (2005)
Szirmai, J.: The optimal ball and horoball packings to the Coxeter honeycombs in the hyperbolic \(d\)-space. Beitr. Algebra Geom. 48, 35–47 (2007)
Szirmai, J.: The densest geodesic ball packing by a type of Nil lattices. Beitr. Algebra Geom. 48, 383–397 (2007)
Szirmai, J.: The densest translation ball packing by fundamental lattices in Sol space. Beitr. Algebra Geom. 51, 353–373 (2010)
Szirmai, J.: Horoball packings to the totally asymptotic regular simplex in the hyperbolic n-space. Aequationes Math. 85, 471–482 (2013)
Szirmai, J.: Horoball packings and their densities by generalized simplicial density function in the hyperbolic space. Acta Math. Hung. 136, 39–55 (2012)
Szirmai, J.: Regular prism tilings in \({\tilde{\bf S}{\bf L_2R}}\) space. Aequationes Math. 88, 67–79 (2014)
Szirmai, J.: Simply transitive geodesic ball packings to \(\mathbf{S^2\times R}\) space groups generated by glide reflections. Annali di Matematica Pura ed Applicata 193, 1201–1211 (2014)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kozma, R.T., Szirmai, J. New Lower Bound for the Optimal Ball Packing Density in Hyperbolic 4-Space. Discrete Comput Geom 53, 182–198 (2015). https://doi.org/10.1007/s00454-014-9634-1
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00454-014-9634-1