English
Related papers

Related papers: Menger's Theorem in bidirected graphs

200 papers

Menger's theorem - the maximum number of vertex-disjoint $X$-$Y$ paths is equal to the minimum size of an $X$-$Y$ separator - is generally not true in bidirected graphs. We prove that Menger's theorem holds true if we take the nontrivial…

Combinatorics · Mathematics 2025-11-18 Ebrahim Ghorbani , Jana Katharina Nickel , Florian Reich

Polat generalised Menger's theorem -- the maximum number of vertex-disjoint paths between two sets $A$ and $B$ equals the minimum size of an $A$-$B$ separator -- to ends of undirected graphs. In this paper we extend Menger's theorem to ends…

Combinatorics · Mathematics 2026-04-13 Florian Reich

The Known Menger's theorem states that in a finite graph, the size of a minimum separator set of any pair of vertices is equal to the maximum number of disjoint paths that can be found between these two vertices. In this paper, we study the…

Discrete Mathematics · Computer Science 2019-04-16 Mouhamad El Joubbeh

We prove that Menger's theorem is valid for infinite graphs, in the following strong form: let $A$ and $B$ be two sets of vertices in a possibly infinite digraph. Then there exist a set $\cp$ of disjoint $A$-$B$ paths, and a set $S$ of…

Combinatorics · Mathematics 2007-12-03 Ron Aharoni , Eli Berger

Menger's Edge Theorem asserts that there exist $k$ pairwise edge-disjoint paths between two vertices in an undirected graph if and only if a deletion of any $k-1$ or less edges does not disconnect these two vertices. Alternatively, there…

Combinatorics · Mathematics 2022-04-05 Avraham Goldstein

Menger's well-known theorem from 1927 characterizes when it is possible to find $k$ vertex-disjoint paths between two sets of vertices in a graph $G$. Recently, Georgakopoulos and Papasoglu and, independently, Albrechtsen, Huynh, Jacobs,…

Combinatorics · Mathematics 2025-01-16 Tung Nguyen , Alex Scott , Paul Seymour

A (directed) temporal graph is a (directed) graph whose edges are available only at specific times during its (discretized) lifetime $\tau$. In this setting, we ask that walks respect the temporal aspect by defining $\textit{temporal…

Discrete Mathematics · Computer Science 2025-10-15 Allen Ibiapina , Raul Lopes , Andrea Marino , Ana Silva

We prove Menger-type results in which the obtained paths are pairwise non-adjacent, both for graphs of bounded maximum degree and, more generally, for graphs excluding a topological minor. We further show better bounds in the subcubic case,…

Combinatorics · Mathematics 2025-10-29 Kevin Hendrey , Sergey Norin , Raphael Steiner , Jérémie Turcotte

Recently, bidirected graphs have received increasing attention from the graph theory community with both structural and algorithmic results. Bidirected graphs are a generalization of directed graphs, consisting of an undirected graph…

Combinatorics · Mathematics 2025-12-16 Tara Abrishami , Nathan Bowler , Attila Joó , Florian Reich , Qiuzhenyu Tao

Menger's Theorem is a fundamental result in graph theory. It states that if in a graph $G$ with distinguished sets of terminal vertices $S$ and $T$ there are no $k$ pairwise vertex-disjoint $S$-$T$ paths, then there is a set of less than…

Combinatorics · Mathematics 2026-05-13 Václav Blažej , Michał Pilipczuk , Evangelos Protopapas

We give an approximate Menger-type theorem for when a graph $G$ contains two $X-Y$ paths $P_1$ and $P_2$ such that $P_1 \cup P_2$ is an induced subgraph of $G$. More generally, we prove that there exists a function $f(d) \in O(d)$, such…

Combinatorics · Mathematics 2024-05-24 Sandra Albrechtsen , Tony Huynh , Raphael W. Jacobs , Paul Knappe , Paul Wollan

Let $A$ and $B$ be sets of vertices in a graph $G$. Menger's theorem states that for every positive integer $k$, either there exists a collection of $k$ vertex-disjoint paths between $A$ and $B$, or $A$ can be separated from $B$ by a set of…

Combinatorics · Mathematics 2023-09-18 Peter Gartland , Tuukka Korhonen , Daniel Lokshtanov

A directed network connecting a set A to a set B is a digraph containing an a-b path for each a in A and b in B. Vertices in the directed network not in A or B are called Steiner points. We show that in a finitely compact metric space in…

Metric Geometry · Mathematics 2008-10-10 Konrad J Swanepoel

Menger's theorem tells us that if $S,T$ are sets of vertices in a graph $G$, then (for $k\ge0$) either there are $k+1$ vertex-disjoint paths between $S$ and $T$, or there is a set of $k$ vertices separating $S$ and $T$. But what if we want…

Combinatorics · Mathematics 2025-09-11 Tung Nguyen , Alex Scott , Paul Seymour

A bisection of a graph is a bipartition of its vertex set such that the two resulting parts differ in size by at most 1, and its size is the number of edges that connect vertices in the two parts. The perfect matching condition and…

Combinatorics · Mathematics 2024-11-19 Jianfeng Hou , Shufei Wu , Yuanyuan Zhong

Coarse graph theory concerns finding 'coarse' analogues of graph theory theorems, replacing disjointness with being far apart. One of the most interesting open questions is to find a coarse analogue of Menger's theorem, which characterizes…

Combinatorics · Mathematics 2025-08-21 Tung Nguyen , Alex Scott , Paul Seymour

Answering a question of Diestel, we develop a topological notion of gammoids in infinite graphs which, unlike traditional infinite gammoids, always define a matroid. As our main tool, we prove for any infinite graph $G$ with vertex sets $A$…

Combinatorics · Mathematics 2014-04-02 Johannes Carmesin

A labelled, undirected graph is a graph whose edges have assigned labels, from a specific set. Given a labelled, undirected graph, the well-known minimum labelling spanning tree problem is aimed at finding the spanning tree of the graph…

Discrete Mathematics · Computer Science 2018-07-03 Jose' Andres Moreno Perez , Sergio Consoli

Menger's theorem says that, for $k\ge0$, if $S, T$ are sets of vertices in a graph $G$, then either there are $k + 1$ vertex-disjoint paths between $S$ and $T$, or there is a set X of at most $k$ vertices such that every $S$-$T$ path passes…

Combinatorics · Mathematics 2025-09-10 Tung Nguyen , Alex Scott , Paul Seymour

The classical Menger's theorem states that in any undirected (or directed) graph $G$, given a pair of vertices $s$ and $t$, the maximum number of vertex (edge) disjoint paths is equal to the minimum number of vertices (edges) needed to…

Data Structures and Algorithms · Computer Science 2015-09-21 Ashutosh Rai , M. S. Ramanujan , Saket Saurabh
‹ Prev 1 2 3 10 Next ›