Abstract
In the view-obstruction problem, congruent, closed convex bodies centred at the points\(\frac{1}{2},{\text{ }}...{\text{ , }}\frac{{\text{1}}}{{\text{2}}} + \mathbb{Z}^n \) in ℝn are expanded uniformly until they block all rays from the origin into the open positive cone. The central problem is to determine the minimal blocking size. In the case of spheres of diameter 1 and cubes of side 1 these values are known forn=2, 3 and 4. Here we show that in ℝ5, this value for the sphere of diameter 1 is\(\sqrt {41/42} \).
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References
Chen, Y. G.: On a conjecture in Diophantine approximations, III. J. Number Theory39, 91–103 (1991).
Chen, Y. G.: The view-obstruction problem for 4-dimensional spheres. Amer. J. Math.116, 1381–1419 (1994).
Cusick, T. W.: View-obstruction problems. Aequations Math.9, 165–170 (1973).
Dumir, V. C., Hans-Gill, R. J.: View-obstruction problem for 3-dimensional spheres. Mh. Math.101, 279–290 (1986).
Dumir, V. C., Hans-Gill, R. J., Wilker, J. B.: Contributions to a general theory of view-obstruction problems. Can. J. Math.45, 517–536 (1993).
Dumir, V. C., Hans-Gill, R. J., Wilker, J. B.: A Markoff type chain for the view-obstruction problem for spheres in ℝ4. Mh. Math.118, 205–217 (1994).
Dumir, V. C., Hans-Gill, R. J., Wilker, Contributions to a general theory of view-obstruction problems. II. J. Number Theory (to appear).
Gruber, P. M., Lekkerkerker, C. G.: Geometry of Numbers, 2nd edn., Amsterdam.
Mahler, K.: On reduced positive definite quaternary quadratic forms. Nieuw Archief voor Wiskunde (2)22, 207–212 (1946).
Wills, J. M.: Zur simultanen homogenen diophantischen Approximation I. Mh. Math.72, 254–263 (1968).
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Dumir, V.C., Hans-Gill, R.J. & Wilker, J.B. The view-obstruction problem for spheres in ℝ5 . Monatshefte für Mathematik 122, 21–34 (1996). https://doi.org/10.1007/BF01298453
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DOI: https://doi.org/10.1007/BF01298453