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In this paper, we present some spectral sufficient conditions for a graph to be Hamilton-connected in terms of the spectral radius or signless Laplacian spectral radius of the graph. Our results improve some previous work.

Combinatorics · Mathematics 2017-11-09 Qiannan Zhou , Ligong Wang , Yong Lu

In this paper we establish some spectral conditions for a graph to be Hamilton-connected in terms of the spectral radius of the adjacency matrix or the signless Laplacian of the graph or its complement. For the existence of Hamiltonian…

Combinatorics · Mathematics 2014-09-19 Gui-Dong Yu , Yi-Zheng Fan

In this paper, we present a spectral sufficient condition for a graph to be Hamilton-connected in terms of signless Laplacian spectral radius with large minimum degree.

Combinatorics · Mathematics 2017-12-01 Qiannan Zhou , Ligong Wang , Yong Lu

In this paper, we study the Hamiltonicity of graphs with large minimum degree. Firstly, we present some conditions for a simple graph to be Hamilton-connected and traceable from every vertex in terms of the spectral radius of the graph or…

Combinatorics · Mathematics 2017-11-29 Guidong Yu , Yi Fang , Yizheng Fan , Gaixiang Cai

A graph $G$ is $k$-edge-Hamiltonian if any collection of vertex-disjoint paths with at most $k$ edges altogether belong to a Hamiltonian cycle in $G$. A graph $G$ is $k$-Hamiltonian if for all $S\subseteq V(G)$ with $|S|\le k$, the subgraph…

Combinatorics · Mathematics 2024-04-09 Yongtao Li , Yuejian Peng

In this paper, we give sufficient conditions on the spectral radius for a bipartite graph to Hamiltonian and traceable, which expand the results of Lu, Liu and Tian (2012) [10]. Furthermore, we also present tight sufficient conditions on…

Combinatorics · Mathematics 2015-07-07 Ruifang Liu , Wai Chee Shiu , Jie Xue

In this paper, first, we establish a sufficient condition for a bipartite graph to be Hamilton-connected. Furthermore, we also give two sufficient conditions on distance signless Laplacian spectral radius for a graph to be…

Combinatorics · Mathematics 2016-10-25 Qiannan Zhou , Ligong Wang

This paper presents sufficient conditions for Hamiltonian paths and cycles in graphs. Letting $\lambda\left( G\right) $ denote the spectral radius of the adjacency matrix of a graph $G,$ the main results of the paper are: (1) Let $k\geq1,$…

Combinatorics · Mathematics 2016-11-08 Vladimir Nikiforov

A graph $G$ is $k$-factor-critical if $G-S$ has a perfect matching for any $k$-subset $S$ of the vertex set of $G$. In this paper, we investigate the factor-criticality of graphs with fixed minimum degree and provide sufficient conditions…

Combinatorics · Mathematics 2024-01-03 Jin Cai , Bo Zhou

A graph $G$ is $k$-path-coverable if its vertex set $V(G)$ can be covered by $k$ or fewer vertex disjoint paths. In this paper, using the $Q$-index of a connected graph $G$, we present a tight sufficient condition for $G$ with fixed minimum…

Combinatorics · Mathematics 2021-09-16 Tao Cheng , Lihua Feng , Yongtao Li , Weijun Liu

Let G be a graph and let \Delta,\delta be the maximum and minimum degrees of G respectively, where \Delta/\delta<c<\sqrt{2} and c is a constant. In this paper we establish a sufficient spectral condition for the graph G to be Hamiltonian,…

Combinatorics · Mathematics 2012-07-31 Yi-Zheng Fan , Gui-Dong Yu

In this paper, we establish a tight sufficient condition for the Hamiltonicity of graphs with large minimum degree in terms of the signless Laplacian spectral radius and characterize all extremal graphs. Moreover, we prove a similar result…

Combinatorics · Mathematics 2017-10-25 Yawen Li , Yao liu , Xing Peng

A factor of a graph is a spanning subgraph. Spectral sufficient conditions are provided via spectral radius and signless Laplacian spectral radius for graphs with (i) a matching of given size (particularly, $1$-factor) containing any given…

Combinatorics · Mathematics 2024-01-25 Jin Cai , Bo Zhou

A graph $G$ is called $k$-factor-critical if after deleting any $k$ vertices the remaining subgraph still has a perfect matching. Fan and Lin [Adv. in Appl. Math. 174 (2026) 103019] posed an adjacency spectral condition for a graph with…

Combinatorics · Mathematics 2026-05-27 Jiaxu Zhong , Yong Lu

This survey is two-fold. We first report new progress on the spectral extremal results on the Tur\'{a}n type problems in graph theory. More precisely, we shall summarize the spectral Tur\'{a}n function in terms of the adjacency spectral…

Combinatorics · Mathematics 2022-05-13 Yongtao Li , Weijun Liu , Lihua Feng

In this paper, we discuss the Hamiltonicity of graphs in terms of Wiener index, hyper-Wiener index and Harary index of their quasi-complement or complement. Firstly, we give some sufficient conditions for an balanced bipartite graph with…

Combinatorics · Mathematics 2018-04-10 Guidong Yu , Lifang Ren , Gaixiang Cai

There have been researches on sufficient spectral conditions for Hamiltonian properties and path-coverable properties of graphs. Utilizing the Bondy-Chv\'atal closure, we provide a unified approach to study sufficient graph eigenvalue…

Combinatorics · Mathematics 2020-05-11 Muhuo Liu , Yang Wu , Hong-Jian Lai

A hypergraph $H$ is hamiltonian-connected if for any distinct vertices $x$ and $y$, $H$ contains a hamiltonian Berge path from $x$ to $y$. We find for all $3\leq r<n$, exact lower bounds on minimum degree $\delta(n,r)$ of an $n$-vertex…

Combinatorics · Mathematics 2023-07-17 Alexandr Kostochka , Ruth Luo , Grace McCourt

Let $G$ be a graph and $h: E(G)\rightarrow [0,1]$ be a function. For any two positive integers $a$ and $b$ with $a\leq b$, a fractional $[a,b]$-factor of $G$ with the indicator function $h$ is a spanning subgraph with vertex set $V(G)$ and…

Combinatorics · Mathematics 2023-07-11 Ao Fan , Ruifang Liu , Guoyan Ao

For two integers $r\geq 2$ and $h\geq 0$, the \emph{$h$-extra $r$-component connectivity} $\kappa^h_r(G)$ of a graph $G$ is defined to be the minimum size of a subset of vertices whose removal disconnects $G$, and there are at least $r$…

Combinatorics · Mathematics 2024-07-04 Yu Wang , Dan Li , Huiqiu Lin
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