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Related papers: Uniform Spanning Forests of Planar Graphs

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We consider three probability measures on subsets of edges of a given finite graph $G$, namely those which govern, respectively, a uniform forest, a uniform spanning tree, and a uniform connected subgraph. A conjecture concerning the…

Probability · Mathematics 2007-05-23 G. R. Grimmett , S. N. Winkler

In this paper, we prove that every $n$-vertex connected $K_{1,5}$-free graph $G$ with $\sigma_4(G)\geq n-1$ contains a spanning tree with at most $5$ leaves and branch vertices in total. Moreover, the degree sum condition "$\sigma_4(G)\geq…

Combinatorics · Mathematics 2022-07-12 Pham Hoang Ha , Nguyen Hoang Trang

We consider a uniform spanning tree in a $\delta$-square grid approximation of a planar domain $\Omega$. For given integer $n\ge 2$, we condition the tree on the following $n$-arm event: we pick $n$ branches, emanating from $n$ points…

Probability · Mathematics 2025-12-24 Nathanaël Berestycki , Marcin Lis , Mingchang Liu , Eveliina Peltola

In 2001, Brualdi and Hollingsworth proved that an edge-colored balanced complete bipartite graph Kn,n with a color set C = {1,2,3,..., 2n-1} has a heterochromatic spanning tree if the number of edges colored with colors in R is more than…

Combinatorics · Mathematics 2018-08-10 Kazuhiro Suzuki

In this article we investigate the Uniform Spanning Forest ($\mathsf{USF}$) in the nearest-neighbour integer lattice $\mathbf{Z}^{d+1} = \mathbf{Z}\times \mathbf{Z}^d$ with an assignment of conductances that makes the underlying (Network)…

Probability · Mathematics 2020-09-03 Guillermo Martinez Dibene

The class of all even-hole-free graphs has unbounded tree-width, as it contains all complete graphs. Recently, a class of (even-hole, $K_4$)-free graphs was constructed, that still has unbounded tree-width [Sintiari and Trotignon, 2019].…

Discrete Mathematics · Computer Science 2023-10-30 Pierre Aboulker , Isolde Adler , Eun Jung Kim , Ni Luh Dewi Sintiari , Nicolas Trotignon

We present a determinantal formula for the number of spanning trees of a complete multipartite graph containing a given spanning forest $F$. Our approach relies on the Generalized Matrix Determinant Lemma and Jacobi's formula for the…

Combinatorics · Mathematics 2026-02-04 Wei Wang , Jun Ge

The search of spanning trees with interesting disjunction properties has led to the introduction of edge-disjoint spanning trees, independent spanning trees and more recently completely independent spanning trees. We group together these…

Discrete Mathematics · Computer Science 2017-02-28 Benoit Darties , Nicolas Gastineau , Olivier Togni

A graph is called pseudo-outerplanar if each block has an embedding on the plane in such a way that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another. In this…

Combinatorics · Mathematics 2011-10-20 Xin Zhang , Guizhen Liu , Jian-Liang Wu

The problems of maximizing the spectral radius and the number of spanning trees in a class of bipartite graphs with certain degree constraints are considered. In both the problems, the optimal graph is conjectured to be a Ferrers graph.…

Combinatorics · Mathematics 2018-09-28 Ravindra Bapat

Let $k\ge 2$ be an integer and $T_1,\ldots, T_k$ be spanning trees of a graph $G$. If for any pair of vertices $(u,v)$ of $V(G)$, the paths from $u$ to $v$ in each $T_i$, $1\le i\le k$, do not contain common edges and common vertices,…

Discrete Mathematics · Computer Science 2014-09-23 Benoit Darties , Nicolas Gastineau , Olivier Togni

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

In this paper we construct spanning trees in hyperbolic graphs that represent their hyperbolic compactification in a good way: so that the tree has a bounded number of distinct rays to each boundary point. The bound depends only on the…

Combinatorics · Mathematics 2013-01-31 Matthias Hamann

We show that the spanning tree congestion problem is NP-complete even for proper interval graphs of linear clique-width at most 4.

Data Structures and Algorithms · Computer Science 2026-02-17 Yota Otachi

We show that every graph is spectrally similar to the union of a constant number of forests. Moreover, we show that Spielman-Srivastava sparsifiers are the union of O(logn) forests. This result can be used to estimate boundaries of small…

Data Structures and Algorithms · Computer Science 2018-08-20 Timothy Chu , Michael B. Cohen , Jakub W. Pachocki , Richard Peng

We obtain sufficient conditions for the emergence of spanning and almost-spanning bounded-degree {\sl rainbow} trees in various host graphs, having their edges coloured independently and uniformly at random, using a predetermined palette.…

Combinatorics · Mathematics 2021-05-25 Elad Aigner-Horev , Dan Hefetz , Abhiruk Lahiri

Let $T$ be a tree. A vertex of degree one is a \emph{leaf} of $T$ and a vertex of degree at least three is a \emph{branch vertex} of $T$. A graph is said to be claw-free if it does not contain $K_{1,3}$ as an induced subgraph. In this…

Combinatorics · Mathematics 2025-11-26 Pham Hoang Ha , Nguyen Gia Hien

Recently, Ehrenborg and Van Willenburg defined a class of bipartite graphs that correspond naturally to Ferrers diagrams, and proved several results about them. We give bijective proofs for the (already known) expressions for the number of…

Combinatorics · Mathematics 2007-05-23 Jason Burns

The seminal papers of Edmonds \cite{Egy}, Nash-Williams \cite{NW} and Tutte \cite{Tu} have laid the foundations of the theories of packing arborescences and packing trees. The directed version has been extensively investigated, resulting in…

Combinatorics · Mathematics 2024-11-26 Pierre Hoppenot , Mathis Martin , Zoltán Szigeti

There is a well-known correspondence between infinite trees and ultrametric spaces which can be interpreted as an equivalence of categories and comes from considering the end space of the tree. In this equivalence, uniformly continuous maps…

Geometric Topology · Mathematics 2007-05-23 Álvaro Martínez Pérez , M. A. Morón
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