Ramsey partitions and proximity data structures
Ramsey partitions and proximity data structures
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Ramsey 分区和邻近数据结构
DOI:
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发表时间:
2005
期刊:
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通讯作者:
A. Naor
中科院分区:
文献类型:
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作者:
M. Mendel;A. Naor
This paper addresses the non-linear isomorphic Dvoretzky theorem and the design of good approximate distance oracles for large distortion. We introduce and construct optimal Ramsey partitions, and use them to show that for every epsiv isin (0,1), any n-point metric space has a subset of size n1-epsiv which embeds into Hilbert space with distortion O(1/epsiv). This result is best possible and improves part of the metric Ramsey theorem of Bartal et al. (2005), in addition to considerably simplifying its proof. We use our new Ramsey partitions to design approximate distance oracles with a universal constant query time, closing a gap left open by Thorup and Zwick (2005). Namely, we show that for any n point metric space X, and k ges 1, there exists an O(k)-approximate distance oracle whose storage requirement is O(n1+1k/), and whose query time is a universal constant. We also discuss applications to various other geometric data structures, and the relation to well separated pair decompositions