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相关论文: The matching polynomials and spectral radii of uni…

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In this paper, using the theory of matching polynomial of hypertrees and ordering of hypertrees, we determine the largest spectral radius of hypertrees with $m$ edges and given size of matching.

组合数学 · 数学 2018-10-16 Li Su , Liying Kang , Honghai Li , Erfang Shan

A connected and acyclic hypergraph is called a supertree. In this paper we mainly focus on the spectral radii of uniform supertrees. Li, Shao and Qi determined the first two $k$-uniform supertrees with large spectral radii among all the…

组合数学 · 数学 2015-02-24 Xiying Yuan

Here we study the spectral radii of some linear hypergraphs, that is, the maximum moduli of the eigenvalues of their corresponding adjacency matrices. We determine the hypertrees having the largest to seventh-largest spectral radii. The…

组合数学 · 数学 2023-03-28 Anirban Banerjee , Amitesh Sarkar

An $r$-uniform supertree is a connected and acyclic hypergraph of which each edge has $r$ vertices, where $r\geq 3$. We propose the concept of matching energy for an $r$-uniform hypergraph, which is defined as the sum of the absolute value…

组合数学 · 数学 2022-03-01 W. H. Wang , J. X. Zhou

In this paper we show how the $\alpha$-spectral radius changes under the edge grafting operations on connected $k$-uniform hypergraphs. We characterize the extremal hypertree for $\alpha$-spectral radius among $k$-uniform non-caterpillar…

组合数学 · 数学 2019-05-21 Feifei Wang , Haiying Shan , Zhiyi Wang

Let $\mathcal T (n, k)$ be the set of the $k$-uniform supertrees with $n$ vertices and $m$ edges, where $k\geq 3$, $n\geq 5$ and $m=\frac{n-1}{k-1}$. % Let $m$ be the number of the edges of the supertrees in $\mathcal T (n, k)$, where…

组合数学 · 数学 2023-08-02 Lou-Jun Yu , Wen-Huan Wang

For real $\alpha\in [0,1)$ and a hypergraph $G$, the $\alpha$-spectral radius of $G$ is the largest eigenvalue of the matrix $A_{\alpha}(G)=\alpha D(G)+(1-\alpha)A(G)$, where $A(G)$ is the adjacency matrix of $G$, which is a symmetric…

离散数学 · 计算机科学 2023-03-30 Haiyan Guo , Bo Zhou , Bizhu Lin

We determine the unique hypergraphs with maximum spectral radius among all connected $k$-uniform ($k\geq 3$) unicyclic hypergraphs with matching number at least $z$, and among all connected $k$-uniform ($k\geq 3$) unicyclic hypergraphs with…

组合数学 · 数学 2019-06-26 Guanglong Yu , Chao Yan , Yarong Wu , Hailiang Zhang

For a $hypergraph$ $\mathcal{G}=(V, E)$ consisting of a nonempty vertex set $V=V(\mathcal{G})$ and an edge set $E=E(\mathcal{G})$, its $adjacency$ $matrix$ $\mathcal {A}_{\mathcal{G}}=[(\mathcal {A}_{\mathcal{G}})_{ij}]$ is defined as…

组合数学 · 数学 2023-07-14 Guanglong Yu , Lin Sun

It is well-known that the spectral radius of a connected uniform hypergraph is an eigenvalue of the hypergraph. However, its algebraic multiplicity remains unknown. In this paper, we use the Poisson Formula and matching polynomials to…

组合数学 · 数学 2023-06-30 Lixiang Chen , Changjiang Bu

We describe the structure of those graphs that have largest spectral radius in the class of all connected graphs with a given degree sequence. We show that in such a graph the degree sequence is non-increasing with respect to an ordering of…

组合数学 · 数学 2008-10-07 Tuerker Biyikoglu , Josef Leydold

This paper investigates the influence of two graft transformations on the distance spectral radius of connected uniform hypergraphs. Specifically, we study $k$-uniform hypertrees with given size, maximum degree and number of vertices of…

组合数学 · 数学 2024-03-15 Xiaoqi Liu , Haiying Shan

We study the effect of three types of graft transformations to increase or decrease the distance spectral radius of uniform hypergraphs, and we determined the unique $k$-uniform hypertrees with maximum, second maximum, minimum and second…

组合数学 · 数学 2016-02-29 Hongying Lin , Bo Zhou

Let $G$ be a $k$-uniform hypergraph with vertex set $V(G)$ and edge set $E(G)$. A connected and acyclic hypergraph is called a supertree. For $0\leq\alpha<1$, the $\alpha$-spectral radius of $G$ is the largest $H$-eigenvalue of $\alpha…

组合数学 · 数学 2022-06-08 Chang Liu , Jianping Li

The spectral radius of a uniform hypergraph $G$ is the the maximum modulus of the eigenvalues of the adjacency tensor of $G$. For $k\ge 2$, among connected $k$-uniform hypergraphs with $m\ge 1$ edges, we show that the $k$-uniform loose path…

谱理论 · 数学 2018-08-28 Jianbin Zhang , Jianping Li , Haiyan Guo

In this paper we investigate the hypergraphs whose spectral radii attain the maximum among all uniform hypergraphs with given number of edges. In particular we characterize the hypergraph(s) with maximum spectral radius over all unicyclic…

组合数学 · 数学 2017-09-07 Yi-Zheng Fan , Ying-Ying Tan , Xi-Xi Peng , An-Hong Liu

Let $S_{1}(m, d, k)$ be the $k$-uniform supertree obtained from a loose path $P:v_{1}, e_{1}, v_{2}, \ldots,v_{d}, e_{d}, v_{d+1}$ with length $d$ by attaching $m-d$ edges at vertex $v_{\lfloor\frac{d}{2}\rfloor+1}.$ Let $\mathbb{S}(m,d,k)$…

组合数学 · 数学 2018-11-22 Cunxiang Duan , Ligong Wang , Peng Xiao

Let A(G) be the adjacency tensor (hypermatrix) of uniform hypergraph G. The maximum modulus of the eigenvalues of A(G) is called the spectral radius of G. In this paper, the conjecture of Fan et al. in [5] related to compare the spectral…

组合数学 · 数学 2016-05-09 Liying Kang , Lele Liu , Liqun Qi , Xiying Yuan

Let $n,m$ be integers such that $1\leq m\leq (n-2)/2$ and let $[n]=\{1,\ldots,n\}$. Let $\mathcal{G}=\{G_1,\ldots,G_{m+1}\}$ be a family of graphs on the same vertex set $[n]$. In this paper, we prove that if for any $i\in [m+1]$, the…

组合数学 · 数学 2022-05-10 Mingyang Guo , Hongliang Lu , Xinxin Ma , Xiao Ma

In this paper, we study some extremal problems of three kinds of spectral radii of $k$-uniform hypergraphs (the adjacency spectral radius, the signless Laplacian spectral radius and the incidence $Q$-spectral radius). We call a connected…

谱理论 · 数学 2014-05-29 Honghai Li , Jiayu Shao , Liqun Qi
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