Better Distance Preservers and Additive Spanners
Better Distance Preservers and Additive Spanners
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更好的距离保持器和附加扳手
DOI:
10.1145/3490147
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发表时间:
2021
影响因子:
1.3
通讯作者:
Williams, Virginia Vassilevska
中科院分区:
文献类型:
--
作者:
Bodwin, Greg;Williams, Virginia Vassilevska
We study two popular ways to sketch the shortest path distances of an input graph. The first isdistance preservers, which are sparse subgraphs that agree with the distances of the original graph on a given set of demand pairs. Prior work on distance preservers has exploited only a simple structural property of shortest paths, calledconsistency, stating that one can break shortest path ties such that no two paths intersect, split apart, and then intersect again later. We prove that consistency alone is not enough to understand distance preservers, by showing both a lower bound on the power of consistency and a new general upper bound that polynomially surpasses it. Specifically, our new upper bound is that anypdemand pairs in ann-node undirected unweighted graph have a distance preserver on O(n2/3p2/3+np1/3edges. We leave a conjecture that the right bound isO(n2/3p2/3+n) or better.The second part of this paper leverages these distance preservers in a new construction ofadditive spanners, which are subgraphs that preserve all pairwise distances up to an additive error function. We give improved error bounds for spanners with relatively few edges; for example, we prove that all graphs have spanners onO(n)edges with +O(n3/7 + ε) error. Our construction can be viewed as an extension of the popular path-buying framework to clusters of larger radii.
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DOI:
--
发表时间:
2013
期刊:
ACM-SIAM Symposium on Discrete Algorithms
影响因子:
--
作者:
S. Chechik
通讯作者:
S. Chechik
DOI:
--
发表时间:
1993
期刊:
Proceedings of 1993 IEEE 34th Annual Foundations of Computer Science
影响因子:
--
作者:
E. Cohen
通讯作者:
E. Cohen
影响因子:
1.3
作者:
Michael Elkin
通讯作者:
Michael Elkin
DOI:
10.4230/lipics.icalp.2017.64
发表时间:
2017
期刊:
ArXiv
影响因子:
--
作者:
M. B. T. Knudsen
通讯作者:
M. B. T. Knudsen
DOI:
10.1145/1011767.1011791
发表时间:
2004
期刊:
ACM Transactions on Algorithms (TALG)
影响因子:
--
作者:
Michael Elkin;Jian Zhang
通讯作者:
Jian Zhang