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Let $G$ be a graph and let $f$ be a positive integer-valued function on $V(G)$. In this paper, we show that if for all $S\subseteq V(G)$, $\omega(G\setminus S)<\sum_{v\in S}(f(v)-2)+2+\omega(G[S])$, then $G$ has a spanning tree $T$…

Combinatorics · Mathematics 2022-05-10 Morteza Hasanvand

The celebrated Erd\H{o}s-Hajnal conjecture states that for every proper hereditary graph class $\mathcal{G}$ there exists a constant $\varepsilon = \varepsilon(\mathcal{G}) > 0$ such that every graph $G \in \mathcal{G}$ contains a clique or…

Combinatorics · Mathematics 2017-10-25 Anita Liebenau , Marcin Pilipczuk

A generalized $t$-pyramid is a graph obtained from a certain kind of tree (a subdivided star or a subdivided cubic caterpillar) and the line graph of a subdivided cubic caterpillar by identifying simplicial vertices. We prove that for every…

Combinatorics · Mathematics 2025-04-04 Tara Abrishami , Bogdan Alecu , Maria Chudnovsky , Sepehr Hajebi , Sophie Spirkl

Uniform spanning trees are a statistical model obtained by taking the set of all spanning trees on a given graph (such as a portion of a cubic lattice in d dimensions), with equal probability for each distinct tree. Some properties of such…

Statistical Mechanics · Physics 2009-11-10 N. Read

We consider the class of graphs for which the edge connectivity is equal to the maximum number of edge-disjoint spanning trees, and the natural generalization to matroids, where the cogirth is equal to the number of disjoint bases. We…

Combinatorics · Mathematics 2014-02-10 Robert F. Bailey , Mike Newman , Brett Stevens

Recently, so-called treebased phylogenetic networks have gained considerable interest in the literature, where a treebased network is a network that can be constructed from a phylogenetic tree, called the base tree, by adding additional…

Populations and Evolution · Quantitative Biology 2019-11-28 Mareike Fischer , Michelle Galla , Lina Herbst , Yangjing Long , Kristina Wicke

Let $G$ be a nontrivial connected graph of order $n$, and $k$ an integer with $2\leq k\leq n$. For a set $S$ of $k$ vertices of $G$, let $\kappa (S)$ denote the maximum number $\ell$ of edge-disjoint trees $T_1,T_2,...,T_\ell$ in $G$ such…

Combinatorics · Mathematics 2010-12-30 Shasha Li , Wei Li , Xueliang Li

The generalized $k$-connectivity $\kappa_k(G)$ of a graph $G$, introduced by Hager in 1985, is a natural generalization of the concept of connectivity $\kappa(G)$, which is just for $k=2$. Total graph is generalized line graph and a large…

Combinatorics · Mathematics 2016-10-04 Yinkui Li

We present a concept called the branch-depth of a connectivity function, that generalizes the tree-depth of graphs. Then we prove two theorems showing that this concept aligns closely with the notions of tree-depth and shrub-depth of graphs…

Combinatorics · Mathematics 2020-11-05 Matt DeVos , O-joung Kwon , Sang-il Oum

The problem of spanning trees is closely related to various interesting problems in the area of statistical physics, but determining the number of spanning trees in general networks is computationally intractable. In this paper, we perform…

Statistical Mechanics · Physics 2012-04-23 Zhongzhi Zhang , Bin Wu , Yuan Lin

In this paper, we explore a taxonomy of connectivity for space-like structures. It is inspired by isolating posets of connected pieces of a space and examining its embedding in the ambient space. The taxonomy includes in its scope all…

General Topology · Mathematics 2026-05-11 Jean F. Du Plessis , Zurab Janelidze , Bernardus A. Wessels

A graph $G$ is called equiarboreal if the number of spanning trees containing a given edge in $G$ is independent of the choice of edge. In [Combinatorica 1(2) (1981) 163--167], Godsil proved that any graph which is a colour class in an…

Combinatorics · Mathematics 2025-12-30 Wensheng Sun , Yujun Yang , Shou-Jun Xu

Graham and Pollak showed that the determinant of the distance matrix of a tree $T$ depends only on the number of vertices of $T$. Graphical distance, a function of pairs of vertices, can be generalized to ``Steiner distance'' of sets $S$ of…

Combinatorics · Mathematics 2023-06-02 Joshua Cooper , Gabrielle Tauscheck

We prove that every connected graph with $s$ vertices of degree~1 and 3 and $t$ vertices of degree at least~4 has a spanning tree with at least ${1\over 3}t +{1\over 4}s+{3\over 2}$ leaves. We present infinite series of graphs showing that…

Combinatorics · Mathematics 2014-05-29 Dmitri Karpov

The complexity of a finite connected graph is its number of spanning trees; for a non-connected graph it is the product of complexities of its connected components. If $G$ is an infinite graph with cofinite free ${\mathbb Z}^d$-symmetry,…

Combinatorics · Mathematics 2016-02-10 Daniel S. Silver , Susan G. Williams

We obtain the numbers of spanning trees on the Sierpinski gasket $SG_d(n)$ with dimension $d$ equal to two, three and four. The general expression for the number of spanning trees on $SG_d(n)$ with arbitrary $d$ is conjectured. The numbers…

Statistical Mechanics · Physics 2009-11-11 Shu-Chiuan Chang , Lung-Chi Chen

In a graph, a spanning tree is said to be a tree t-spanner of the graph if the distance between any two vertices in is at most times their distance in . The tree t-spanner has many applications in networks and distributed environments. In…

Discrete Mathematics · Computer Science 2014-08-12 Sambhu Charan Barman , Sukumar Mondal , Madhumangal Pal

Generalized synchronization is plausibly the most complex form of synchronization. Previous studies have revealed the existence of weak or strong forms of generalized synchronization depending on the multi- or mono-valued nature of the…

Chaotic Dynamics · Physics 2024-01-23 Christophe Letellier , Ludovico Minati , Irene Sendina-Nadal , I. Leyva

In response to a well-known open question ``Does every complete geometric graph on $2n\/$ vertices have a partition of its edge set into $n\/$ plane spanning trees?" we provide an affirmative answer when the complete geometry graph is in…

Combinatorics · Mathematics 2019-06-14 Hazim Michman Trao , Gek L. Chia , Niran Abbas Ali , Adem Kilicman

The generalized $k$-connectivity $\kappa_k(G)$ of a graph $G$, introduced by Hager in 1985, is a nice generalization of the classical connectivity. Recently, as a natural counterpart, we proposed the concept of generalized…

Combinatorics · Mathematics 2015-09-01 Xueliang Li , Yaping Mao