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arXiv 1005.2639math.CO
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三距离和更高距离集上的界

Bounds on three- and higher-distance sets

Oleg R. Musin, Hiroshi Nozaki

摘要:

度量空间M中的有限集X称为s-距离集,如果X中任意两个不同点之间的距离集的大小为s。s-距离集的主要问题是确定固定s和M的s-距离集的最大基数。本文改进了n-球面中s-距离集的已知上界,其中s= 3,4.特别地,我们确定了n=7和21的三距离集的最大基数。给出了S-距离集在Hamming空间和Johnson空间中的最大基数。

英文摘要:

A finite set X in a metric space M is called an s-distance set if the set of distances between any two distinct points of X has size s. The main problem for s-distance sets is to determine the maximum cardinality of s-distance sets for fixed s and M. In this paper, we improve the known upper bound for s-distance sets in n-sphere for s=3,4. In particular, we determine the maximum cardinalities of three-distance sets for n=7 and 21. We also give the maximum cardinalities of s-distance sets in the Hamming space and the Johnson space for several s and dimensions.

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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