On Strong Diameter Padded Decompositions

Fuente: arXiv
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Autore principale: Filtser, Arnold
Natura: Preprint
Pubblicazione: 2019
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author Filtser, Arnold
author_facet Filtser, Arnold
contents Given a weighted graph $G=(V,E,w)$, a partition of $V$ is $Δ$-bounded if the diameter of each cluster is bounded by $Δ$. A distribution over $Δ$-bounded partitions is a $β$-padded decomposition if every ball of radius $γΔ$ is contained in a single cluster with probability at least $e^{-β\cdotγ}$. The weak diameter of a cluster $C$ is measured w.r.t. distances in $G$, while the strong diameter is measured w.r.t. distances in the induced graph $G[C]$. The decomposition is weak/strong according to the diameter guarantee. Formerly, it was proven that $K_r$ minor free graphs admit weak decompositions with padding parameter $O(r)$, while for strong decompositions only $O(r^2)$ padding parameter was known. Furthermore, for the case of a graph $G$, for which the induced shortest path metric $d_G$ has doubling dimension $d$, a weak $O(d)$-padded decomposition was constructed, which is also known to be tight. For the case of strong diameter, nothing was known. We construct strong $O(r)$-padded decompositions for $K_r$ minor free graphs, matching the state of the art for weak decompositions. Similarly, for graphs with doubling dimension $d$ we construct a strong $O(d)$-padded decomposition, which is also tight. We use this decomposition to construct strong $\left(O(d),\tilde{O}(d)\right)$ sparse cover scheme for such graphs. Our new decompositions and cover have implications to approximating unique games, the construction of light and sparse spanners, and for path reporting distance oracles.
format Preprint
id arxiv_https___arxiv_org_abs_1906_09783
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle On Strong Diameter Padded Decompositions
Filtser, Arnold
Data Structures and Algorithms
Computational Geometry
Given a weighted graph $G=(V,E,w)$, a partition of $V$ is $Δ$-bounded if the diameter of each cluster is bounded by $Δ$. A distribution over $Δ$-bounded partitions is a $β$-padded decomposition if every ball of radius $γΔ$ is contained in a single cluster with probability at least $e^{-β\cdotγ}$. The weak diameter of a cluster $C$ is measured w.r.t. distances in $G$, while the strong diameter is measured w.r.t. distances in the induced graph $G[C]$. The decomposition is weak/strong according to the diameter guarantee. Formerly, it was proven that $K_r$ minor free graphs admit weak decompositions with padding parameter $O(r)$, while for strong decompositions only $O(r^2)$ padding parameter was known. Furthermore, for the case of a graph $G$, for which the induced shortest path metric $d_G$ has doubling dimension $d$, a weak $O(d)$-padded decomposition was constructed, which is also known to be tight. For the case of strong diameter, nothing was known. We construct strong $O(r)$-padded decompositions for $K_r$ minor free graphs, matching the state of the art for weak decompositions. Similarly, for graphs with doubling dimension $d$ we construct a strong $O(d)$-padded decomposition, which is also tight. We use this decomposition to construct strong $\left(O(d),\tilde{O}(d)\right)$ sparse cover scheme for such graphs. Our new decompositions and cover have implications to approximating unique games, the construction of light and sparse spanners, and for path reporting distance oracles.
title On Strong Diameter Padded Decompositions
topic Data Structures and Algorithms
Computational Geometry
url https://arxiv.org/abs/1906.09783