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Illuminating and covering convex bodies. (English) Zbl 1303.52009

Summary: Covering numbers of convex bodies based on homothetical copies and related illumination numbers are well-known in combinatorial geometry and, for example, related to Hadwiger’s famous covering problem. Similar numbers can be defined by using proper translates instead of homothets, and even more related concepts make sense. On these lines we introduce some new covering and illumination numbers of convex bodies, present their properties and compare them with each other as well as with already known numbers. Finally, some suggestive examples illustrate that these new illumination numbers are interesting and non-trivial.

MSC:

52C15 Packing and covering in \(2\) dimensions (aspects of discrete geometry)

References:

[1] Bezdek, K., Hadwiger-Levi’s covering problem revisited, (New Trends in Discrete and Computational Geometry. New Trends in Discrete and Computational Geometry, Algorithms Combin., vol. 10 (1993), Springer: Springer Berlin), 199-233 · Zbl 0798.52004
[2] Bezdek, K., The illumination conjecture and its extensions, Period. Math. Hungar., 53, 59-69 (2006) · Zbl 1127.52026
[3] Bezdek, K., (Classical Topics in Discrete Geometry. Classical Topics in Discrete Geometry, CMS Books in Mathematics (2010), Springer: Springer New York) · Zbl 1207.52001
[4] Bezdek, K.; Böröczky, K.; Kiss, Gy., On the successive illumination parameters of convex bodies, Period. Math. Hungar., 53, 71-82 (2006) · Zbl 1127.52025
[5] Bezdek, K.; Litvak, A. E., On the vertex index of convex bodies, Adv. Math., 215, 626-641 (2007) · Zbl 1131.46011
[6] Boltyanski, V.; Martini, H.; Soltan, P., Excursions into Combinatorial Geometry (1997), Springer: Springer Berlin, Heidelberg, New York · Zbl 0877.52001
[7] Boltyanski, V.; Martini, H.; Soltan, V., On Grünbaum’s conjecture about inner illumination of convex bodies, Discrete Comput. Geom., 22, 403-410 (1999) · Zbl 0940.52004
[8] Dekster, B. V., Illumination and exposition of a convex \(n\)-dimensional body depending on its sharpness, Acta Math. Sci. Ser. B Engl. Ed., 22, 189-198 (2002) · Zbl 1014.52007
[9] Kiss, Gy.; de Wet, P. O., Notes on the illumination parameters of convex polytopes, Contrib. Discrete Math., 7, 58-67 (2012) · Zbl 1317.52006
[10] Larman, D.; Sójka, G., On the number of minor illuminations required to cover the boundary of a convex body in \(R^n\), Rev. Roumaine Math. Pures Appl., 51, 21-42 (2006) · Zbl 1119.52300
[11] Lassak, M.; Martini, H.; Spirova, M., On translative coverings of convex bodies, Rocky Mountain J. Math. (2014), in press · Zbl 1305.52022
[12] Martini, H.; Soltan, V., Combinatorial problems on the illumination of convex bodies, Aequationes Math., 57, 121-152 (1999) · Zbl 0937.52006
[13] Martini, H.; Wenzel, W., Illumination and visibility problems in terms of closure operators, Beiträge Algebra Geom., 45, 607-614 (2004) · Zbl 1074.52001
[14] Martini, H.; Wenzel, W., Symmetrization of closure operators and visibility, Ann. Comb., 9, 431-450 (2005) · Zbl 1099.06003
[15] Moreno, J. P.; Seeger, A., External analysis of boundary points of convex sets: illumination and visibility, Math. Scand., 105, 265-286 (2009) · Zbl 1187.49010
[16] Naszódi, M., Fractional illumination of convex bodies, Contrib. Discrete Math., 4, 83-88 (2009) · Zbl 1189.52005
[17] Soltan, V., An illumination problem, Studia Sci. Math. Hungar., 29, 25-32 (1994) · Zbl 0815.52007
[18] Swanepoel, K. J., Quantitative illumination of convex bodies and vertex degrees of geometric Steiner minimal trees, Mathematika, 52, 47-52 (2005) · Zbl 1105.52005
[19] Szabó, L., Recent results on illumination problems, (Bolyai Soc. Math. Stud., Vol. 6 (1997), Janos Bolyai Math. Soc.: Janos Bolyai Math. Soc. Budapest), 207-221 · Zbl 0886.52005
[20] Szabó, L.; Talata, I., An illumination problem for convex polyhedra, Studia Sci. Math. Hungar., 32, 349-353 (1996) · Zbl 0881.52004
[21] Weißbach, B., Invariante Beleuchtung konvexer Körper, Beiträge Algebra Geom., 37, 9-15 (1996) · Zbl 0889.52010
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