English
Related papers

Related papers: Improved exploration of temporal graphs

200 papers

We consider the problem of assigning appearing times to the edges of a digraph in order to maximize the (average) temporal reachability between pairs of nodes. Motivated by the application to public transit networks, where edges cannot be…

Discrete Mathematics · Computer Science 2025-01-22 Filippo Brunelli , Pierluigi Crescenzi , Laurent Viennot

Let $G$ be a finite, simple, and undirected graph of order $n$ and average degree $d$. Up to terms of smaller order, we characterize the minimal intervals $I$ containing $d$ that are guaranteed to contain some vertex degree. In particular,…

Combinatorics · Mathematics 2023-01-20 Johannes Pardey , Dieter Rautenbach

We introduce a new graph-theoretic concept in the area of network monitoring. A set $M$ of vertices of a graph $G$ is a \emph{distance-edge-monitoring set} if for every edge $e$ of $G$, there is a vertex $x$ of $M$ and a vertex $y$ of $G$…

Data Structures and Algorithms · Computer Science 2022-09-26 Florent Foucaud , Shih-Shun Kao , Ralf Klasing , Mirka Miller , Joe Ryan

A graph $G$ is terminal-pairable with respect to a demand multigraph $D$ on the same vertex set as $G$, if there exists edge-disjoint paths joining the end vertices of every demand edge of $D$. In this short note, we improve the upper bound…

Combinatorics · Mathematics 2017-08-24 António Girão , Gábor Mészáros

We give a nearly optimal sublinear-time algorithm for approximating the size of a minimum vertex cover in a graph G. The algorithm may query the degree deg(v) of any vertex v of its choice, and for each 1 <= i <= deg(v), it may ask for the…

Data Structures and Algorithms · Computer Science 2011-10-06 Krzysztof Onak , Dana Ron , Michal Rosen , Ronitt Rubinfeld

In this paper, we study the complexity of the periodic temporal graph realization problem with respect to upper bounds on the fastest path durations among its vertices. This constraint with respect to upper bounds appears naturally in…

Data Structures and Algorithms · Computer Science 2025-04-22 George B. Mertzios , Hendrik Molter , Nils Morawietz , Paul G. Spirakis

Given a graph $G$ and two vertices $s$ and $t$ in it, {\em graph reachability} is the problem of checking whether there exists a path from $s$ to $t$ in $G$. We show that reachability in directed layered planar graphs can be decided in…

Data Structures and Algorithms · Computer Science 2015-01-26 Diptarka Chakraborty , Raghunath Tewari

A vertex set $S$ is a generalized $k$-independent set if the induced subgraph $G[S]$ contains no tree on $k$ vertices. The generalized $k$-independence number $\alpha_k(G)$ is the maximum size of such a set. For a tree $T$ with $n$…

Combinatorics · Mathematics 2025-09-17 Jing Huang , Jiaxin Tang

A graph is temporally connected if there exists a strict temporal path, i.e. a path whose edges have strictly increasing labels, from every vertex $u$ to every other vertex $v$. In this paper we study temporal design problems for undirected…

Data Structures and Algorithms · Computer Science 2022-05-03 Nina Klobas , George B. Mertzios , Hendrik Molter , Paul G. Spirakis

We study the problem of finding the $k$ most similar trajectories to a given query trajectory. Our work is inspired by the work of Grossi et al. [6] that considers trajectories as walks in a graph. Each visited vertex is accompanied by a…

Data Structures and Algorithms · Computer Science 2020-10-20 Lutz Oettershagen , Anne Driemel , Petra Mutzel

Let $G$ be an undirected, bounded degree graph with $n$ vertices. Fix a finite graph $H$, and suppose one must remove $\varepsilon n$ edges from $G$ to make it $H$-minor free (for some small constant $\varepsilon > 0$). We give an…

Discrete Mathematics · Computer Science 2018-08-29 Akash Kumar , C. Seshadhri , Andrew Stolman

A well known theorem in graph theory states that every graph $G$ on $n$ vertices and minimum degree at least $d$ contains a path of length at least $d$, and if $G$ is connected and $n\ge 2d+1$ then $G$ contains a path of length at least…

Combinatorics · Mathematics 2019-03-12 Yue Ma , Xinmin Hou , Jun Gao

The Burning Number Conjecture claims that for every connected graph $G$ of order $n,$ its burning number satisfies $b(G) \le \lceil \sqrt{n} \rceil.$ While the conjecture remains open, we prove that it is asymptotically true when the order…

We show that for any constant $\Delta \ge 2$, there exists a graph $G$ with $O(n^{\Delta / 2})$ vertices which contains every $n$-vertex graph with maximum degree $\Delta$ as an induced subgraph. For odd $\Delta$ this significantly improves…

Combinatorics · Mathematics 2019-02-20 Noga Alon , Rajko Nenadov

Let $d,n\in \mathbb{N}$ be such that $d=\omega(1)$, and $d\le n^{1-a}$ for some constant $a>0$. Consider a $d$-regular graph $G=(V, E)$ and the random graph process that starts with the empty graph $G(0)$ and at each step $G(i)$ is obtained…

Combinatorics · Mathematics 2024-09-25 Sahar Diskin , Anna Geisler

In this paper we study the computational complexity of the Upward Planarity Extension problem, which takes in input an upward planar drawing $\Gamma_H$ of a subgraph $H$ of a directed graph $G$ and asks whether $\Gamma_H$ can be extended to…

Data Structures and Algorithms · Computer Science 2019-02-19 Giordano Da Lozzo , Giuseppe Di Battista , Fabrizio Frati

One of the fundamental results in graph minor theory is that for every planar graph $H$, there is a minimum integer $f(H)$ such that graphs with no minor isomorphic to $H$ have treewidth at most $f(H)$. A lower bound for ${f(H)}$ can be…

Combinatorics · Mathematics 2026-01-16 J. Pascal Gollin , Kevin Hendrey , Sang-il Oum , Bruce Reed

Treedepth, a more restrictive graph width parameter than treewidth and pathwidth, plays a major role in the theory of sparse graph classes. We show that there exists a constant $C$ such that for every positive integers $a,b$ and a graph…

Discrete Mathematics · Computer Science 2019-09-19 Wojciech Czerwiński , Wojciech Nadara , Marcin Pilipczuk

Let G be an input graph with n vertices and m edges and let k be a fixed parameter. We provide a single exponential FPT algorithm with running time O(c^kn(n+m)), c= min {18,k} that turns graph G into an interval graph by deleting at most k…

Data Structures and Algorithms · Computer Science 2016-02-09 Arash Rafiey

We consider the problem of testing graph cluster structure: given access to a graph $G=(V, E)$, can we quickly determine whether the graph can be partitioned into a few clusters with good inner conductance, or is far from any such graph?…

Data Structures and Algorithms · Computer Science 2018-09-19 Ashish Chiplunkar , Michael Kapralov , Sanjeev Khanna , Aida Mousavifar , Yuval Peres