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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

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

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 determine the maximal Laplacian and signless Laplacian spectral radii for graphs with fixed number of vertices and domination number, and characterize the extremal graphs respectively.

Combinatorics · Mathematics 2013-10-29 Rundan Xing , Bo Zhou

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, we present a sharp upper and lower bounds for the signless Laplacian spectral radius of graphs in terms of clique number. Moreover, the extremal graphs which attain the upper and lower bounds are characterized. In addition,…

Combinatorics · Mathematics 2012-09-17 Bian He , Ya-Lei Jin , Xiao-Dong Zhang

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

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

We obtain new bounds for the Laplacian spectral radius of a signed graph. Most of these new bounds have a dependence on edge sign, unlike previously known bounds, which only depend on the underlying structure of the graph. We then use some…

Combinatorics · Mathematics 2011-03-25 Nathan Reff

Let $G=(V(G),E(G))$ be a simple graph, where $V(G)$ and $E(G)$ are the vertex set and the edge set of $G$, respectively. The number of components of $G$ is denoted by $c(G)$. Let $t$ be a positive real number, and a connected graph $G$ is…

Combinatorics · Mathematics 2025-04-14 Xiangge Liu , Yong Lu , Caili Jia , Qiannan Zhou , Yue Cui

In this paper we determine the graph whose least eigenvalue of signless Laplacian attains the minimum or maximum among all connected non-bipartite graphs of fixed order and given number of pendant vertices. Thus we obtain a lower bound and…

Combinatorics · Mathematics 2014-09-19 Yi-Zheng Fan , Yi Wang , Huan Guo

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

Tur\'{a}n type extremal problem is how to maximize the number of edges over all graphs which do not contain fixed forbidden subgraphs. Similarly, spectral Tur\'{a}n type extremal problem is how to maximize (signless Laplacian) spectral…

Combinatorics · Mathematics 2020-07-20 Ming-Zhu Chen , A-Ming Liu , Xiao-Dong Zhang

M. Aouchiche and P. Hansen proposed the distance Laplacian and the distance signless Laplacian of a connected graph [Two Laplacians for the distance matrix of a graph, LAA 439 (2013) 21{33]. In this paper, we obtain three theorems on the…

Combinatorics · Mathematics 2013-08-16 Wenxi Hong , Lihua You

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 $k$-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

Let $F_{a_1,\dots,a_k}$ be a graph consisting of $k$ cycles of odd length $2a_1+1,\dots, 2a_k+1$, respectively which intersect in exactly a common vertex, where $k\geq1$ and $a_1\ge a_2\ge \cdots\ge a_k\ge 1$. In this paper, we present a…

Combinatorics · Mathematics 2021-08-10 Ming-Zhu Chen , A-Ming Liu , Xiao-Dong Zhang

Let $k$ and $n$ be two nonnegative integers with $n\equiv0$ (mod 2), and let $G$ be a graph of order $n$ with a 1-factor. Then $G$ is said to be $k$-extendable for $0\leq k\leq\frac{n-2}{2}$ if every matching in $G$ of size $k$ can be…

Combinatorics · Mathematics 2023-03-30 Sizhong Zhou , Yuli Zhang

In this paper we define signless Laplacian matrix of a hypergraph and obtain structural properties from its eigenvalues. We generalize several known results for graphs, relating the spectrum of this matrix with structural parameters of the…

Spectral Theory · Mathematics 2024-08-12 Kauê Cardoso , Vilmar Trevisan
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