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Related papers: On low degree k-ordered graphs

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A k-ranking of a graph G is a labeling of the vertices of G with values from 1,...,k such that any path joining two vertices with the same label contains a vertex having a higher label. The tree-depth of G is the smallest value of k for…

Combinatorics · Mathematics 2016-04-05 Michael D. Barrus , John Sinkovic

Boesch and Chen (SIAM J. Appl. Math., 1978) introduced the cut-version of the generalized edge-connectivity, named $k$-edge-connectivity. For any integer $k$ with $2\leq k\leq n$, the {\em $k$-edge-connectivity} of a graph $G$, denoted by…

Discrete Mathematics · Computer Science 2019-01-21 Yuefang Sun , Xiaoyan Zhang , Zhao Zhang

The concept of pendant-tree $k$-connectivity $\tau_k(G)$ of a graph $G$, introduced by Hager in 1985, is a generalization of classical vertex-connectivity. Let $f(n,k,\ell)$ be the minimal number of edges of a graph $G$ of order $n$ with…

Combinatorics · Mathematics 2016-04-26 Yaping Mao

A connected graph $G$ is said to be $k$-connected if it has more than $k$ vertices and remains connected whenever fewer than $k$ vertices are deleted. In this paper, for a connected graph $G$ with sufficiently large order, we present a…

Combinatorics · Mathematics 2021-09-17 Peng-Li Zhang , Lihua Feng , Weijun Liu , Xiao-Dong Zhang

The interaction between local traits and global frameworks of mathematical objects has long endured as a central theme in various mathematical domains. A graph \(G\) is referred to as locally linear provided that the subgraph induced by the…

Combinatorics · Mathematics 2026-04-16 Feng Liu , Leilei Zhang

The minimum semi-degree of a digraph D is the minimum of its minimum outdegree and its minimum indegree. We show that every sufficiently large digraph D with minimum semi-degree at least n/2 +k-1 is k-linked. The bound on the minimum…

Combinatorics · Mathematics 2007-05-23 Daniela Kühn , Deryk Osthus

A graph of order $n$ is said to be \emph{$k$-factor-critical} ($0\leq k <n$) if the removal of any $k$ vertices results in a graph with a perfect matching. A $k$-factor-critical graph $G$ is \emph{minimal} if $G-e$ is not…

Combinatorics · Mathematics 2025-11-12 Qiuli Li , Fuliang Lu , Heping Zhang

A well-quasi-order is an order which contains no infinite decreasing sequence and no infinite collection of incomparable elements. In this paper, we consider graph classes defined by excluding one graph as contraction. More precisely, we…

Combinatorics · Mathematics 2016-12-20 Marcin Kamiński , Jean-Florent Raymond , Théophile Trunck

We describe an algorithm for the exhaustive generation of non-isomorphic graphs with a given number $k \ge 0$ of hamiltonian cycles, which is especially efficient for small $k$. Our main findings, combining applications of this algorithm…

Combinatorics · Mathematics 2019-07-16 Jan Goedgebeur , Barbara Meersman , Carol T. Zamfirescu

A graph of order $n$ is said to be $k$-\emph{factor-critical} $(0\le k<n)$ if the removal of any $k$ vertices results in a graph with a perfect matching. A $k$-factor-critical graph $G$ is \emph{minimal} if $G-e$ is not $k$-factor-critical…

Combinatorics · Mathematics 2026-03-12 Kevin Pereyra

An edge-colored graph $G$ is $k$-color connected if, between each pair of vertices, there exists a path using at least $k$ different colors. The $k$-color connection number of $G$, denoted by $cc_{k}(G)$, is the minimum number of colors…

Combinatorics · Mathematics 2017-03-29 Hong Chang , Zhong Huang , Xueliang Li

A weighted (directed) graph is a (directed) graph with integer weights assigned to its vertices and edges. The weight of a subgraph is the sum of weights of vertices and edges in the subgraph. The problem of determining the largest order…

Combinatorics · Mathematics 2024-07-02 Ajit A. Diwan

For an ordered set $W=\{w_1,w_2,...,w_k\}$ of vertices and a vertex $v$ in a connected graph $G$, the ordered $k$-vector $r(v|W):=(d(v,w_1),d(v,w_2),.,d(v,w_k))$ is called the (metric) representation of $v$ with respect to $W$, where…

Combinatorics · Mathematics 2011-03-21 Mohsen Jannesari , Behnaz Omoomi

In 1980, Jackson proved that every 2-connected $k$-regular graph with at most $3k$ vertices is Hamiltonian. This result has been extended in several papers. In this note, we determine the minimum number of vertices in a connected…

Combinatorics · Mathematics 2015-08-06 Daniel W. Cranston , Suil O

Let $G$ be a finite group. The co-prime order graph of $G$ is the graph whose vertex set is $G$, and two distinct vertices $x,y$ are adjacent if gcd$(o(x),o(y))$ is either $1$ or a prime, where $o(x)$ and $o(y)$ are the orders of $x$ and…

Combinatorics · Mathematics 2021-09-28 Xuanlong Ma , Zhonghua Wang

Hasunuma [J. Graph Theory 102 (2023) 423-435] conjectured that for any tree $T$ of order $m$, every $k$-connected (or $k$-edge-connected) graph $G$ with minimum degree at least $k+m-1$ contains a tree $T'\cong T$ such that $G-E(T')$ is…

Combinatorics · Mathematics 2023-03-08 Qing Yang , Yingzhi Tian

A $k$-connected set in an infinite graph, where $k > 0$ is an integer, is a set of vertices such that any two of its subsets of the same size $\ell \leq k$ can be connected by $\ell$ disjoint paths in the whole graph. We characterise the…

Combinatorics · Mathematics 2020-09-21 J. Pascal Gollin , Karl Heuer

Let $F$ and $G$ be simple finite oriented graphs (without symmetric arcs). A graph $G$ is called $F$-irregular if any two distinct vertices in $G$ belong to a different number of subgraphs of $G$ isomorphic to $F$. In this paper, we…

Combinatorics · Mathematics 2026-05-22 Tatiana Dovzhenok , Ilya Lukashenko , Yahor Filiuta

Kronk introduced the $l$-path hamiltonianicity of graphs in 1969. A graph is $l$-path Hamiltonian if every path of length not exceeding $l$ is contained in a Hamiltonian cycle. We have shown that if $P=uvz$ is a 2-path of a 2-connected,…

Combinatorics · Mathematics 2023-11-10 Xia Li , Weihua Yang , Bo Zhang , Shuang Zhao

A k-ranking of a graph G is a labeling of the vertices of G with values from {1,...,k} such that any path joining two vertices with the same label contains a vertex having a higher label. The tree-depth of G is the smallest value of k for…

Combinatorics · Mathematics 2015-02-19 Michael D. Barrus , John Sinkovic