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Related papers: Finding Light Spanners in Bounded Pathwidth Graphs

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A \emph{$\nu$-reliable spanner} of a metric space $(X,d)$, is a (dominating) graph $H$, such that for any possible failure set $B\subseteq X$, there is a set $B^+$ just slightly larger $|B^+|\le(1+\nu)\cdot|B|$, and all distances between…

Data Structures and Algorithms · Computer Science 2023-08-01 Arnold Filtser , Yuval Gitlitz , Ofer Neiman

A $t$-{\em spanner} $H$ of a weighted graph $G=(V,E,w)$ is a subgraph that approximates all pairwise distances up to a factor of $t$. The {\em lightness} of $H$ is defined as the ratio between the weight of $H$ to that of the minimum…

Data Structures and Algorithms · Computer Science 2019-05-08 Michael Elkin , Arnold Filtser , Ofer Neiman

Let $P$ be a set of $n$ points in $\mathbb{R}^d$, and let $\varepsilon,\psi \in (0,1)$ be parameters. Here, we consider the task of constructing a $(1+\varepsilon)$-spanner for $P$, where every edge might fail (independently) with…

Computational Geometry · Computer Science 2025-02-19 Sariel Har-Peled , Maria C. Lusardi

In FOCS 2017, Borradaille, Le, and Wulff-Nilsen addressed a long-standing open problem by proving that minor-free graphs have light spanners. Specifically, they proved that every $K_h$-minor-free graph has a $(1+\epsilon)$-spanner of…

Data Structures and Algorithms · Computer Science 2025-04-24 Greg Bodwin , Gary Hoppenworth , Zihan Tan

There has recently been significant interest in fault tolerant spanners, which are spanners that still maintain their stretch guarantees after some nodes or edges fail. This work has culminated in an almost complete understanding of the…

Data Structures and Algorithms · Computer Science 2025-04-28 Greg Bodwin , Michael Dinitz , Ama Koranteng , Lily Wang

A tree $\sigma$-spanner of a positively real-weighted $n$-vertex and $m$-edge undirected graph $G$ is a spanning tree $T$ of $G$ which approximately preserves (i.e., up to a multiplicative stretch factor $\sigma$) distances in $G$. Tree…

Data Structures and Algorithms · Computer Science 2017-10-05 Davide Bilò , Feliciano Colella , Luciano Gualà , Stefano Leucci , Guido Proietti

Hopsets and spanners are fundamental graph structures, playing a key role in shortest path computation, distributed communication, and more. A (near-exact) hopset for a given graph $G$ is a (small) subset of weighted edges $H$ that when…

Data Structures and Algorithms · Computer Science 2022-11-15 Shimon Kogan , Merav Parter

Graph spanners are well-studied and widely used both in theory and practice. In a recent breakthrough, Chechik and Wulff-Nilsen [CW18] improved the state-of-the-art for light spanners by constructing a $(2k-1)(1+\epsilon)$-spanner with…

Data Structures and Algorithms · Computer Science 2022-01-20 Stephen Alstrup , Søren Dahlgaard , Arnold Filtser , Morten Stöckel , Christian Wulff-Nilsen

A tree t-spanner of an unweighted graph G is a spanning tree T such that for every two vertices their distance in T is at most t times their distance in G. Given an unweighted graph G and a positive integer t as input, the tree t-spanner…

Data Structures and Algorithms · Computer Science 2013-10-17 N. S. Narayanaswamy , G. Ramakrishna

Consider a setting where possibly sensitive information sent over a path in a network is visible to every {neighbor} of the path, i.e., every neighbor of some node on the path, thus including the nodes on the path itself. The exposure of a…

Data Structures and Algorithms · Computer Science 2012-12-27 Shiri Chechik , M. P. Johnson , Merav Parter , David Peleg

We study two popular ways to sketch the shortest path distances of an input graph. The first is distance preservers, which are sparse subgraphs that agree with the distances of the original graph on a given set of demand pairs. Prior work…

Data Structures and Algorithms · Computer Science 2021-06-08 Greg Bodwin , Virginia Vassilevska Williams

Given an undirected $n$-node unweighted graph $G = (V, E)$, a spanner with stretch function $f(\cdot)$ is a subgraph $H\subseteq G$ such that, if two nodes are at distance $d$ in $G$, then they are at distance at most $f(d)$ in $H$.…

Data Structures and Algorithms · Computer Science 2013-01-11 Marek Cygan , Fabrizio Grandoni , Telikepalli Kavitha

Given a weighted graph $G(V,E)$ and $t \ge 1$, a subgraph $H$ is a \emph{$t$--spanner} of $G$ if the lengths of shortest paths in $G$ are preserved in $H$ up to a multiplicative factor of $t$. The \emph{subsetwise spanner} problem aims to…

Discrete Mathematics · Computer Science 2019-04-03 Reyan Ahmed , Keaton Hamm , Mohammad Javad Latifi Jebelli , Stephen Kobourov , Faryad Darabi Sahneh , Richard Spence

Seminal works on light spanners over the years have provided spanners with optimal lightness in various graph classes, such as general graphs, Euclidean spanners, and minor-free graphs. Three shortcomings of previous works on light spanners…

Data Structures and Algorithms · Computer Science 2023-03-16 Hung Le , Shay Solomon

We consider additive spanners of unweighted undirected graphs. Let $G$ be a graph and $H$ a subgraph of $G$. The most na\"ive way to construct an additive $k$-spanner of $G$ is the following: As long as $H$ is not an additive $k$-spanner…

Data Structures and Algorithms · Computer Science 2014-11-25 Mathias Bæk Tejs Knudsen

Given an undirected unweighted graph $G = (V, E)$ on $n$ vertices and $m$ edges, a subgraph $H\subseteq G$ is a spanner of $G$ with stretch function $f: \mathbb{R}_+ \rightarrow \mathbb{R}_+$, if for every pair $s, t$ of vertices in $V$,…

Data Structures and Algorithms · Computer Science 2024-10-18 Zihan Tan , Tianyi Zhang

The tree spanner problem for a graph $G$ is as follows: For a given integer $k$, is there a spanning tree $T$ of $G$ (called a tree $k$-spanner) such that the distance in $T$ between every pair of vertices is at most $k$ times their…

Combinatorics · Mathematics 2025-02-07 Lan Lin , Yixun Lin

In general the problem of finding a miminum spanning tree for a weighted directed graph is difficult but solvable. There are a lot of differences between problems for directed and undirected graphs, therefore the algorithms for undirected…

Discrete Mathematics · Computer Science 2008-01-16 V. A. Buslov , V. A. Khudobakhshov

Let $G = (V,E,w)$ be a weighted undirected graph on $|V| = n$ vertices and $|E| = m$ edges, let $k \ge 1$ be any integer, and let $\epsilon < 1$ be any parameter. We present the following results on fast constructions of spanners with…

Data Structures and Algorithms · Computer Science 2021-08-03 Hung Le , Shay Solomon

Spanners are fundamental graph structures that sparsify graphs at the cost of small stretch. In particular, in recent years, many sequential algorithms constructing additive all-pairs spanners were designed, providing very sparse…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-06-03 Keren Censor-Hillel , Ami Paz , Noam Ravid