Abstract
Nil geometry is one of the eight 3-dimensional Thurston geometries, it can be derived from W. Heisenberg’s famous real matrix group. The aim of this paper is to study lattice-like ball coverings in Nil space. We introduce the notion of the density of the considered coverings and give upper and lower estimates to it, moreover in Section 3, we formulate a conjecture for the ball arrangement of the least dense latticelike geodesic ball covering and give its covering density \({\triangle \approx 1.42900615}\). The homogeneous 3-spaces have a unified interpretation in the projective 3-sphere and in our work we will use this projective model.
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Molnár E.: The projective interpretation of the eight 3-dimensional homogeneous geometries. Beiträge Algebra Geom. 38(no. 2), 261–288 (1997)
E. Molnár, On projective models of Thurston geometries, some relevant notes on Nil orbifolds and manifolds, Sib. ‘Elektron. Mat. Izv.7 (2010), 491–498, (http://semr.math.nsc.ru).
E. Molnár, I. Prok and J. Szirmai, Classification of tile-transitive 3-simplex tilings and their realizations in homogeneous spaces, in: Non-Euclidean geometries, János Bolyai Memorial Volume, Ed. A. Prekopa and E. Molnár, 321–363, Math. Appl. (N. Y.) 581, Springer, New York, 2006.
J. Pallagi, B. Schultz and J. Szirmai, Equidistant surfaces in Nil space, Stud. Univ. Žilina Math. Ser. (2012), to appear.
Scott P.: The geometries of 3-manifolds, Bull. London Math. Soc. 15, 401–487 (1983) (Russian translation: Moscow ”Mir” 1986.)
Szirmai J.: The optimal ball and horoball packings to the Coxeter honeycombs in the hyperbolic d-space. Beiträge Algebra Geom. 48(no. 1), 35–47 (2007)
Szirmai J.: The densest geodesic ball packing by a type of Nil lattices. Beiträge Algebra Geom. 48(no. 2), 383–398 (2007)
Szirmai J.: The densest translation ball packing by fundamental lattices in Sol space. Beiträge Algebra Geom. 51(no. 2), 353–371 (2010)
J. Szirmai Geodesic ball packing in S 2 × R space for generalized Coxeter space groups, Beiträge Algebra Geom. 52 (2011), 413–430.
J. Szirmai, Geodesic ball packing in H 2 × R space for generalized Coxeter space groups. Math. Commun. (2012), to appear.
J. Szirmai, Lattice-like translation ball packings in Nil space, Publ. Math. Debrecen (2012), to appear.
W. P. Thurston, Three-dimensional geometry and topology, Vol. 1, Edited by Silvio Levy, Princeton Mathematical Series, 35, Princeton University Press, Princeton, NJ, 1997.
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The research was supported by the grant TÁMOP - 4.2.2.B-10/1, 2010-0009.
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Szirmai, J. On Lattice Coverings of Nil Space by Congruent Geodesic Balls. Mediterr. J. Math. 10, 953–970 (2013). https://doi.org/10.1007/s00009-012-0211-7
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DOI: https://doi.org/10.1007/s00009-012-0211-7