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Consider the complete n-vertex graph whose edge-lengths are independent exponentially distributed random variables. Simultaneously for each pair of vertices, put a constant flow between them along the shortest path. Each edge gets some…

Probability · Mathematics 2007-08-06 David J. Aldous , Shankar Bhamidi

In this paper, motivated by a question posed in \cite{AH}, we introduce strongly biconvex graphs as a subclass of weakly chordal and bipartite graphs. We give a linear time algorithm to find an induced matching for such graphs and we prove…

Commutative Algebra · Mathematics 2019-05-08 Sara Saeedi Madani , Dariush Kiani

Simple drawings of graphs are those in which each pair of edges share at most one point, either a common endpoint or a proper crossing. In this paper we study the problem of extending a simple drawing $D(G)$ of a graph $G$ by inserting a…

Computational Geometry · Computer Science 2019-08-27 Alan Arroyo , Martin Derka , Irene Parada

We show that if a graph contains few induced copies of a given graph then its edges are distribited unevenly.

Combinatorics · Mathematics 2007-05-23 Vladimir Nikiforov

In the sufficiently sparse case, we find the probability that a uniformly random bipartite graph with given degree sequence contains no edge from a specified set of edges. This enables us to enumerate loop-free digraphs and oriented graphs…

Combinatorics · Mathematics 2026-01-09 Catherine Greenhill , Mahdieh Hasheminezhad , Isaiah Iliffe , Brendan D. McKay

We give a polynomial-time algorithm that, with input a graph $G$ and two vertices $u,v$ of $G$, decides whether there is an induced $uv$-path that is longer than the shortest $uv$-path.

Combinatorics · Mathematics 2020-05-27 Eli Berger , Paul Seymour , Sophie Spirkl

We consider the problem of decomposing the edges of a directed graph into as few paths as possible. There is a natural lower bound for the number of paths needed in an edge decomposition of a directed graph $D$ in terms of its degree…

Combinatorics · Mathematics 2021-09-29 Alberto Espuny Díaz , Viresh Patel , Fabian Stroh

In new progress on conjectures of Stein, and Addario-Berry, Havet, Linhares Sales, Reed and Thomass\'e, we prove that every oriented graph with all in- and out-degrees greater than 5k/8 contains an alternating path of length k. This…

Combinatorics · Mathematics 2025-09-08 Jozef Skokan , Mykhaylo Tyomkyn

The inducibility of a graph represents its maximum density as an induced subgraph over all possible sequences of graphs of size growing to infinity. This invariant of graphs has been extensively studied since its introduction in $1975$ by…

Optimization and Control · Mathematics 2025-12-19 Daniel Brosch , Diane Puges

How long a monotone path can one always find in any edge-ordering of the complete graph $K_n$? This appealing question was first asked by Chv\'atal and Koml\'os in 1971, and has since attracted the attention of many researchers, inspiring a…

Combinatorics · Mathematics 2019-09-20 Matija Bucic , Matthew Kwan , Alexey Pokrovskiy , Benny Sudakov , Tuan Tran , Adam Zsolt Wagner

We show that every graph has an induced pseudoforest of at least $n-m/4.5$ vertices, an induced partial 2-tree of at least $n-m/5$ vertices, and an induced planar subgraph of at least $n-m/5.2174$ vertices. These results are constructive,…

Computational Geometry · Computer Science 2015-07-16 Glencora Borradaile , David Eppstein , Pingan Zhu

We study separating systems of the edges of a graph where each member of the separating system is a path. We conjecture that every $n$-vertex graph admits a separating path system of size $O(n)$ and prove this in certain interesting special…

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

Fix an oriented graph H, and let G be a graph with bounded clique number and very large chromatic number. If we somehow orient its edges, must there be an induced subdigraph isomorphic to H? Kierstead and Rodl raised this question for two…

Combinatorics · Mathematics 2018-09-06 Maria Chudnovsky , Alex Scott , Paul Seymour

We determine the probability thresholds for the existence of monotone paths, of finite and infinite length, in random oriented graphs with vertex set $\mathbb N^{[k]}$, the set of all increasing $k$-tuples in $\mathbb N$. These graphs…

Probability · Mathematics 2016-10-05 Pietro Majer , Matteo Novaga

We prove that for every graph H and for every integer s, the class of graphs that do not contain K_s, K_{s,s}, or any subdivision of H as an induced subgraph has bounded expansion; this strengthens a result of Kuhn and Osthus. The argument…

Combinatorics · Mathematics 2017-06-20 Zdeněk Dvořák

We consider random temporal graphs, a version of the classical Erd\H{o}s--R\'enyi random graph G(n,p) where additionally, each edge has a distinct random time stamp, and connectivity is constrained to sequences of edges with increasing time…

Probability · Mathematics 2023-06-21 Nicolas Broutin , Nina Kamčev , Gabor Lugosi

Ramsey proved that for every positive integer $n$, every sufficiently large graph contains an induced $K_n$ or $\overline{K}_n$. Among the many extensions of Ramsey's Theorem there is an analogue for connected graphs: for every positive…

Combinatorics · Mathematics 2023-06-16 Sarah Allred , Guoli Ding , Bogdan Oporowski

Let $G$ be any graph of minimum degree at least $k$, and let $G_p$ be the random subgraph of $G$ obtained by keeping each edge independently with probability $p$. Recently, Krivelevich, Lee and Sudakov showed that if $pk\to\infty$ then with…

Combinatorics · Mathematics 2015-05-12 Oliver Riordan

Borradaile, Le and Sherman-Bennett [Graphs and Combinatorics, 2017] proved that every $n$-vertex $2$-outerplane graph has a set of at least $2n/3$ vertices that induces an outerplane graph. We identify a major flaw in their proof and…

Combinatorics · Mathematics 2026-02-23 Marco D'Elia , Fabrizio Frati