English
Related papers

Related papers: A result on spanning trees with bounded total exce…

200 papers

Let $G=(V,E)$ be a connected graph, where $V=\{v_1, v_2, \cdots, v_n\}$ and $m=|E|$. $d_i$ will denote the degree of vertex $v_i$ of $G$, and $\Delta=\max_{1\leq i \leq n} d_i$. The ABC matrix of $G$ is defined as $M(G)=(m_{ij})_{n \times…

Spectral Theory · Mathematics 2020-04-20 Wenshui Lin , Yiming Zheng , Peifang Fu , Zhangyong Yan , Jia-Bao Liu

The total graph of $G$, $\mathcal T(G)$ is the graph whose set of vertices is the union of the sets of vertices and edges of $G$, where two vertices are adjacent if and only if they stand for either incident or adjacent elements in $G$. Let…

Spectral Theory · Mathematics 2018-06-13 Eber Lenes , Exequiel Mallea-Zepeda , María Robbiano , Jonnathan Rodríguez

A tree $T$, in an edge-colored graph $G$, is called {\em a rainbow tree} if no two edges of $T$ are assigned the same color. A {\em $k$-rainbow coloring}of $G$ is an edge coloring of $G$ having the property that for every set $S$ of $k$…

Combinatorics · Mathematics 2013-10-10 Tingting Liu , Yumei Hu

Let $k\ge 2$ be a positive integer and let $G$ be a simple graph of order $n$ with minimum degree $\delta$. A graph $G$ is said to have property $P(k, d)$ if it contains $k$ edge-disjoint spanning trees and an additional forest $F$ with…

Combinatorics · Mathematics 2026-01-14 Yongbin Gao , Ligong Wang

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

We present a polynomial time algorithm that for any graph G and integer k >= 0, either finds a spanning tree with at least k internal vertices, or outputs a new graph G' on at most 3k vertices and an integer k' such that G has a spanning…

Data Structures and Algorithms · Computer Science 2012-03-06 Fedor V. Fomin , Serge Gaspers , Saket Saurabh , Stéphan Thomassé

We consider lower bounds on the number of spanning trees of connected graphs with degree bounded by $d$. The question is of interest because such bounds may improve the analysis of the improvement produced by memorisation in the runtime of…

Discrete Mathematics · Computer Science 2009-02-13 John Michael Robson

The $r$-expansion of a $k$-uniform hypergraph $H$, denoted by $H^{(+r)}$, is an $r$-uniform hypergraph obtained by enlarging each $k$-edge of $H$ with a set of $r-k$ vertices of degree one. The random Tur\'an number…

Combinatorics · Mathematics 2024-05-21 Jiaxi Nie

Let $\mathcal{G}_{n,r,s}$ denote a uniformly random $r$-regular $s$-uniform hypergraph on the vertex set $\{1,2,\ldots, n\}$. We establish a threshold result for the existence of a spanning tree in $\mathcal{G}_{n,r,s}$, restricting to $n$…

Combinatorics · Mathematics 2023-06-22 Catherine Greenhill , Mikhail Isaev , Gary Liang

Let $G$ be a nontrivial connected graph with an edge-coloring $c: E(G)\rightarrow \{1,2,...,q\},$ $q \in \mathbb{N}$, where adjacent edges may be colored the same. A tree $T$ in $G$ is a $rainbow tree$ if no two edges of $T$ receive the…

Combinatorics · Mathematics 2013-07-04 Lily Chen , Xueliang Li , Kang Yang , Yan Zhao

The connection between the maximum spanning tree in a directed graph and the best dependency tree of a sentence has been exploited by the NLP community. However, for many dependency parsing schemes, an important detail of this approach is…

Computation and Language · Computer Science 2021-06-03 Ran Zmigrod , Tim Vieira , Ryan Cotterell

We compute the total number of spanning trees for the generalized cone of the complete graph $K_n$ and a number of families of some modified bipartite graphs $K_{m,n}$. In particular, we obtain a new method of finding the number of spanning…

Combinatorics · Mathematics 2024-11-06 Zubeyir Cinkir

For a graph $G$, let $t(G)$ denote the maximum number of vertices in an induced subgraph of $G$ that is a tree. Further, for a vertex $v\in V(G)$, let $t^v(G)$ denote the maximum number of vertices in an induced subgraph of $G$ that is a…

Combinatorics · Mathematics 2008-12-15 Florian Pfender

A spanning tree of a graph $G$ is a connected acyclic spanning subgraph of $G$. We consider enumeration of spanning trees when $G$ is a $2$-tree, meaning that $G$ is obtained from one edge by iteratively adding a vertex whose neighborhood…

Discrete Mathematics · Computer Science 2016-07-21 P. Renjith , N. Sadagopan , Douglas B. West

We define an all-$k$-isolating set of a graph to be a set $S$ of vertices such that, if one removes $S$ and all its neighbors, then no component in what remains has order $k$ or more. The case $k=1$ corresponds to a dominating set and the…

Combinatorics · Mathematics 2025-09-16 Geoffrey Boyer , Garrett C. Farrell , Wayne Goddard

The Spanning Tree Congestion (STC) problem is the following NP-hard problem: given a graph $G$, construct a spanning tree $T$ of $G$ minimizing its maximum edge congestion where the congestion of an edge $e\in T$ is the number of edges $uv$…

Data Structures and Algorithms · Computer Science 2026-05-05 Petr Kolman

Let $G$ be a graph and $T$ be a spanning tree of $G$. We use $Q(G)=D(G)+A(G)$ to denote the signless Laplacian matrix of $G$, where $D(G)$ is the diagonal degree matrix of $G$ and $A(G)$ is the adjacency matrix of $G$. The signless…

Combinatorics · Mathematics 2026-03-24 Jiancheng Wu , Sizhong Zhou , Hongxia Liu

A $k$-ranking of a graph $G$ is a labeling of its vertices from $\{1,\ldots,k\}$ such that any nontrivial path whose endpoints have the same label contains a larger label. The least $k$ for which $G$ has a $k$-ranking is the ranking number…

Combinatorics · Mathematics 2014-01-14 Daniel C. McDonald

A tree $t$-spanner of a graph $G$ is a spanning tree of $G$ such that the distance between pairs of vertices in the tree is at most $t$ times their distance in $G$. Deciding tree $t$-spanner admissible graphs has been proved to be tractable…

Discrete Mathematics · Computer Science 2018-01-01 Ioannis Papoutsakis

An edge in a $k$-connected graph $G$ is called {\em $k$-contractible} if the graph $G/e$ obtained from $G$ by contracting $e$ is $k$-connected. Generalizing earlier results on $3$-contractible edges in spanning trees of $3$-connected…

Combinatorics · Mathematics 2016-10-31 Matthias Kriesell , Jens M. Schmidt