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Related papers: Cliques and the Spectral Radius

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In this paper, we determine the graphs whose spectral radius and distance spectral radius attain maximum and minimum among all complements of clique trees. Furthermore, we also determine the graphs whose spectral radius and distance…

Combinatorics · Mathematics 2024-05-31 Xu Chen , Dongjun Fan , Rongxiao Shao , Guoping Wang

We give upper and lower bounds on the spectral radius of a graph in terms of the number of walks. We generalize a number of known results.

Combinatorics · Mathematics 2007-05-23 Vladimir Nikiforov

We give lower bounds on the size and total size of clique partitions of a graph in terms of its spectral radius and minimum degree, and derive a spectral upper bound for the maximum number of edge-disjoint $t$-cliques. The extremal graphs…

Combinatorics · Mathematics 2021-11-05 Jiang Zhou , Edwin R. van Dam

We give some new bounds for the clique and independence numbers of a graph in terms of its eigenvalues.

Combinatorics · Mathematics 2017-01-31 Vladimir Nikiforov

The square of a connected graph $G$ is obtained from $G$ by adding an edge between every pair of vertices at distance $2$. In this paper we give some upper or lower bounds for the spectral radius of the square of connected graphs, trees and…

Combinatorics · Mathematics 2014-04-30 Yi-Zheng Fan , Long Wang

We give a bound on the spectral radius of subgraphs of regular graphs with given order and diameter. We give a lower bound on the smallest eigenvalue of a nonbipartite regular graph of given order and diameter.

Combinatorics · Mathematics 2007-05-25 Vladimir Nikiforov

We study cliques in graphs arising from quadratic forms where the vertices are the elements of the module of the quadratic form and two vertices are adjacent if their difference represents some fixed scalar. We determine structural…

Number Theory · Mathematics 2023-06-13 Nico Lorenz , Marc Christian Zimmermann

In this paper we obtain several tight bounds on different types of alliance numbers of a graph: (global) defensive alliance number, global offensive alliance number and global dual alliance number. In particular, we investigate the…

Combinatorics · Mathematics 2007-05-23 J. A. Rodriguez , J. M. Sigarreta

In this paper, we define a homogeneous polynomial for a general hypergraph, and establish a remarkable connection between clique number and the homogeneous polynomial of a general hypergraph. For a general hypergraph, we explore some…

Combinatorics · Mathematics 2018-11-06 Yuan Hou , An Chang , Lei Zhang

Bicyclic graph is a connected graph in which the number of edges equals the number of vertices plus one. In this paper, we determine the graph which alone maximizes the spectral radii among all the bicyclic graphs on $n$ vertices with fixed…

Combinatorics · Mathematics 2014-02-25 Xiying Yuan

In this paper, we give the relationship between spectral radius and local structures of graphs and hypergraphs. Our work shows that certain local subgraphs (subhypergraphs) must occur when the spectral radius ratio is large. We also give…

Combinatorics · Mathematics 2025-12-02 Jiang Zhou , Changjiang Bu

In this paper, we study how the distance spectral radius behaves when the graph is perturbed by grafting edges. As applications, we also determine the graph with $k$ cut vertices (respectively, $k$ cut edges) with the minimal distance…

Spectral Theory · Mathematics 2010-11-10 Xiaoling Zhang , Chris Godsil

The paper is a brief survey of some recent new results and progress of the Laplacian spectra of graphs and complex networks (in particular, random graph and the small world network). The main contents contain the spectral radius of the…

Combinatorics · Mathematics 2011-11-15 Ya-Hong Chen , Rong-Ying Pan , Xiao-Dong Zhang

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

The spectral radius (or the signless Laplacian spectral radius) of a general hypergraph is the maximum modulus of the eigenvalues of its adjacency (or its signless Laplacian) tensor. In this paper, we firstly obtain a lower bound of the…

Combinatorics · Mathematics 2020-07-28 Cunxiang Duan , Ligong Wang

The $\alpha$-spectral radius of a connected graph $G$ is the spectral radius of $A_\alpha$-matrix of $G$. In this paper, we discuss the methods for comparing $\alpha$-spectral radius of graphs. As applications, we characterize the graphs…

Combinatorics · Mathematics 2021-06-18 F. F. Wang , H. Y. Shan , Y. Y. Zhai

The spectral radius of a graph is the largest modulus of an eigenvalue of its adjacency matrix. Let $\mathcal{C}_{n, e}$ be the set of all the connected simple graphs with $n$ vertices and $n - 1 + e$ edges. Here, we solve the spectral…

Combinatorics · Mathematics 2026-01-26 Ivan Damnjanović

We study the behaviour of clique complexes of graphs under the operation of taking graph powers. As an example we compute the clique complexes of powers of cycles, or, in other words, the independence complexes of circular complete graphs.

Combinatorics · Mathematics 2015-03-19 Michal Adamaszek

We consider a set of cliques in any multipartite graph with two vertices in each part. Moreover, we construct a class of peculiar polytopes. Key words: multipartite graph, clique, polytope.

Combinatorics · Mathematics 2007-05-23 Julia V. Grishicheva , Alexander V. Seliverstov

We study the spectrum of the join of several circulant matrices. We apply our results to compute explicitly the spectrum of certain graphs obtained by joining several circulant graphs.

Combinatorics · Mathematics 2022-06-13 Jacqueline Doan , Jan Minac , Lyle Muller , Tung T. Nguyen , Federico W. Pasini
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