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Related papers: Diameter Computation on (Random) Geometric Graphs

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The girth of a graph, i.e. the length of its shortest cycle, is a fundamental graph parameter. Unfortunately all known algorithms for computing, even approximately, the girth and girth-related structures in directed weighted $m$-edge and…

Data Structures and Algorithms · Computer Science 2018-08-14 Jakub Pachocki , Liam Roditty , Aaron Sidford , Roei Tov , Virginia Vassilevska Williams

Recent research on computing the diameter of geometric intersection graphs has made significant strides, primarily focusing on the 2D case where truly subquadratic-time algorithms were given for simple objects such as unit-disks and…

Computational Geometry · Computer Science 2026-03-24 Timothy M. Chan , Hsien-Chih Chang , Jie Gao , Sándor Kisfaludi-Bak , Hung Le , Da Wei Zheng

It is well known that many random graphs with infinite variance degrees are ultrasmall. More precisely, for configuration models and preferential attachment models where the proportion of vertices of degree at least $k$ is approximately…

Probability · Mathematics 2018-01-31 Francesco Caravenna , Alessandro Garavaglia , Remco van der Hofstad

We study the mixing time of random graphs in the $d$-dimensional toric unit cube $[0,1]^d$ generated by the geographical threshold graph (GTG) model, a generalization of random geometric graphs (RGG). In a GTG, nodes are distributed in a…

Probability · Mathematics 2011-09-21 Andrew Beveridge , Milan Bradonjić

The Randi\'c index of a graph $G$, denoted by $R(G)$, is defined as the sum of $1/\sqrt{d(u)d(v)}$ over all edges $uv$ of $G$, where $d(u)$ denotes the degree of a vertex $u$ in $G$. In this paper, we partially solve two conjectures on the…

Combinatorics · Mathematics 2009-06-30 Xueliang Li , Yongtang Shi

This work addresses a modification of the random geometric graph (RGG) model by considering a set of points uniformly and independently distributed on the surface of a $(d-1)$-sphere with radius $r$ in a $d-$dimensional Euclidean space,…

Physics and Society · Physics 2018-10-03 Alfonso Allen-Perkins

The diameter, radius and eccentricities are natural graph parameters. While these problems have been studied extensively, there are no known dynamic algorithms for them beyond the ones that follow from trivial recomputation after each…

Data Structures and Algorithms · Computer Science 2019-12-18 Bertie Ancona , Monika Henzinger , Liam Roditty , Virginia Vassilevska Williams , Nicole Wein

Computing the diameter of a graph, i.e. the largest distance, is a fundamental problem that is central in fine-grained complexity. In undirected graphs, the Strong Exponential Time Hypothesis (SETH) yields a lower bound on the time vs.…

Data Structures and Algorithms · Computer Science 2023-07-18 Amir Abboud , Mina Dalirrooyfard , Ray Li , Virginia Vassilevska-Williams

We give the first truly subquadratic time algorithm, with $O^*(n^{2-1/18})$ running time, for computing the diameter of an $n$-vertex unit-disk graph, resolving a central open problem in the literature. Our result is obtained as an instance…

Data Structures and Algorithms · Computer Science 2025-10-21 Timothy M. Chan , Hsien-Chih Chang , Jie Gao , Sándor Kisfaludi-Bak , Hung Le , Da Wei Zheng

Given a group $G$, the model $\mathcal{G}(G,p)$ denotes the probability space of all Cayley graphs of $G$ where each element of $G$ is included in the generating set independently at random with probability $p$. In this article, we…

Combinatorics · Mathematics 2026-05-29 Demetres Christofides , Klas Markström , Christina Savvidou

Erd\H{o}s, Pach, Pollack, and Tuza [\textit{J. Combin. Theory Ser. B, 47(1) (1989), 73-79}] proved that the diameter of a connected $n$-vertex graph with minimum degree $\delta$ is at most $\frac{3n}{\delta+1}+O(1)$. The oriented diameter…

Combinatorics · Mathematics 2025-04-15 Garner Cochran , Zhiyu Wang

The $n$-dimensional random twisted hypercube $\mathbf{G}_n$ is constructed recursively by taking two instances of $\mathbf{G}_{n-1}$, with any joint distribution, and adding a random perfect matching between their vertex sets. Benjamini,…

Combinatorics · Mathematics 2024-10-14 Lucas Aragão , Maurício Collares , Gabriel Dahia , João Pedro Marciano

The radius and diameter are fundamental graph parameters. They are defined as the minimum and maximum of the eccentricities in a graph, respectively, where the eccentricity of a vertex is the largest distance from the vertex to another…

Data Structures and Algorithms · Computer Science 2015-06-08 Amir Abboud , Virginia Vassilevska Williams , Joshua Wang

Computing the diameter, and more generally, all eccentricities of an undirected graph is an important problem in algorithmic graph theory and the challenge is to identify graph classes for which their computation can be achieved in…

Data Structures and Algorithms · Computer Science 2024-10-15 Pierre Bergé , Guillaume Ducoffe , Michel Habib

A random algebraic graph is defined by a group $G$ with a uniform distribution over it and a connection $\sigma:G\longrightarrow[0,1]$ with expectation $p,$ satisfying $\sigma(g)=\sigma(g^{-1}).$ The random graph…

Probability · Mathematics 2023-05-10 Kiril Bangachev , Guy Bresler

A graph algorithm is truly subquadratic if it runs in ${\cal O}(m^b)$ time on connected $m$-edge graphs, for some positive $b < 2$. Roditty and Vassilevska Williams (STOC'13) proved that under plausible complexity assumptions, there is no…

Data Structures and Algorithms · Computer Science 2020-10-30 Guillaume Ducoffe

Consider the setting of \emph{randomly weighted graphs}, namely, graphs whose edge weights are chosen independently according to probability distributions with finite support over the non-negative reals. Under this setting, properties of…

Data Structures and Algorithms · Computer Science 2010-03-30 Yuval Emek , Amos Korman , Yuval Shavitt

Many machine learning algorithms used for dimensional reduction and manifold learning leverage on the computation of the nearest neighbours to each point of a dataset to perform their tasks. These proximity relations define a so-called…

Statistical Mechanics · Physics 2020-07-22 Vittorio Erba , Sebastiano Ariosto , Marco Gherardi , Pietro Rotondo

Diameter -- the task of computing the length of a longest shortest path -- is a fundamental graph problem. Assuming the Strong Exponential Time Hypothesis, there is no $O(n^{1.99})$-time algorithm even in sparse graphs [Roditty and…

Data Structures and Algorithms · Computer Science 2020-12-22 Matthias Bentert , André Nichterlein

Due to their broad application to different fields of theory and practice, generalized Petersen graphs $GPG(n,s)$ have been extensively investigated. Despite the regularity of generalized Petersen graphs, determining an exact formula for…

Combinatorics · Mathematics 2023-10-06 Laila Loudiki , Mustapha Kchikech , El Hassan Essaky