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arXiv 0710.4668math.CO
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Tverberg定理的推广

A generalization of Tverberg's Theorem

Micha A. Perles, Moriah Sigron

摘要:

著名的特沃伯格定理指出,如果n >(d+1)(r-1),那么可以将R^d中的任何n个点划分为r个不相交子集,这些子集的凸包有一个公共点。数T(d,r)=(d + 1)(r - 1)+ 1被称为Tverberg数。雷伊问以下问题:如果我们增加一个额外的参数k(1 < k < r+1)是什么样的最小数量的点,我们需要以保证存在一个r分区,他们这样的任何k r凸包相交。这个最小数用T(d,r,k)表示。Reay证明了T(d,r,k)= T(d,r),对所有d,r和k.本文证明了当k > [(d+3)/2 ]-1或d < rk/(r-k)-1时,对于特定值d = 3; r = 4; k = 2和d = 5; r = 3; k = 2,这是成立的。

英文摘要:

The well know theorem of Tverberg states that if n > (d+1)(r-1) then one can partition any set of n points in R^d to r disjoint subsets whose convex hulls have a common point. The numbers T(d,r) = (d + 1)(r - 1) + 1 are known as Tverberg numbers. Reay asks the following question: if we add an additional parameter k (1 < k < r+1) what is the minimal number of points we need in order to guarantee that there exists an r partition of them such that any k of the r convex hulls intersect. This minimal number is denoted by T(d,r,k). Reay conjectured that T(d,r,k) = T(d,r) for all d,r and k. In this article we prove that this is true for the following cases: when k > [ (d+3)/2 ]-1 or when d < rk/(r-k)-1 and for the specific values d = 3; r = 4; k = 2 and d = 5; r = 3; k = 2.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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