Abstract
What is the maximum of the sum of the pairwise (non-obtuse) angles formed by n lines in the Euclidean 3-space? This question was posed by Fejes Tóth in (Acta Math Acad Sci Hung 10:13–19, 1959). Fejes Tóth solved the problem for \({n \leq 6}\), and proved the asymptotic upper bound \({n^{2} \pi /5}\) as \({n \to \infty}\). He conjectured that the maximum is asymptotically equal to \({n^{2} \pi /6}\) as \({n \to \infty}\). The main result of this paper is an upper bound on the sum of the angles of n lines in the Euclidean 3-space that is asymptotically equal to \({3n^{2} \pi /16}\) as \({n \to \infty}\).
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References
Bruckner A. M.: Some relationships between locally superadditive functions and convex functions, Proc. Amer. Math. Soc. 15, 61–65 (1964)
I. Fáry, Sur la courbure totale d’une courbe gauche faisant un nœud Bull. Soc. Math. France 77 (1949), 128–138 (French).
L. Fejes Tóth, Über eine Punktverteilung auf der Kugel, Acta Math. Acad. Sci. Hungar 10 (1959), 13–19 (German).
O. Frostman, A theorem of Fáry with elementary applicatons, Nordisk Mat. Tidskr. 1 (1953), 25–32, 64.
http://mathoverflow.net/questions/173712/maximum-sum-of-angles-between-n-lines. Last accessed: July 30, 2015.
Minghui Jiang, On the sum of distances along a circle, Discrete Math. 308 (2008), 2038–2045.
Larcher H.: Solution of a geometric problem by Fejes Tóth, Michigan Math. J. 9, 45–51 (1962)
F. Nielsen, On the sum of the distances between n points on a sphere., Nordisk Mat. Tidskr. 13 (1965), 45–50 (Danish).
G. Sperling, Lösung einer elementargeometrischen Frage von Fejes Tóth, Arch. Math. 11 (1960), 69–71 (German).
D. Zagier, The dilogarithm function in geometry and number theory, Number theory and related topics (Bombay, 1988), Tata Inst. Fund. Res. Stud. Math., vol. 12, Tata Inst. Fund. Res., Bombay, 1989, pp. 231–249.
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Fodor, F., Vígh, V. & Zarnócz, T. On the angle sum of lines. Arch. Math. 106, 91–100 (2016). https://doi.org/10.1007/s00013-015-0847-1
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DOI: https://doi.org/10.1007/s00013-015-0847-1