Sharp Bounds on Geometric Permutations of Pairwise Disjoint Balls in IRd
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چکیده
(i) We prove that the maximum number of geometric permutations, induced by line transversals to a collection of n pairwise disjoint balls in IR d , is (n d?1). This improves substantially the general upper bound of O(n 2d?2) given in 11]. (ii) We show that the maximum number of geometric permutations of a suuciently large collection of pairwise disjoint unit discs in the plane is 2, improving a previous upper bound of 3 given in 7].
منابع مشابه
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تاریخ انتشار 1998