中文
相关论文

相关论文: On the Spectral properties of power graphs over ce…

200 篇论文

An $L(2,1)$-labelling of a finite graph $\Gamma$ is a function that assigns integer values to the vertices $V(\Gamma)$ of $\Gamma$ (colouring of $V(\Gamma)$ by ${\mathbb{Z}}$) so that the absolute difference of two such values is at least…

群论 · 数学 2021-06-18 Mayank Mishra , Siddhartha Sarkar

For a simple connected graph $ G $ of order $ n $, the normalized Laplacian is a square matrix of order $ n $, defined as $\mathcal{L}(G)= D(G)^{-\frac{1}{2}}L(G)D(G)^{-\frac{1}{2}}$, where $ D(G)^{-\frac{1}{2}} $ is the diagonal matrix…

组合数学 · 数学 2021-07-20 Bilal A. Rather , S. Pirzada , T. A. Chishti , Ahmad M. Alghamdi

The power graph $\mathcal{P}(G)$ of a finite group $G$ is the simple graph with vertex set $G$, in which two distinct vertices are adjacent if one of them is a power of the other. For an integer $n\geq 2$, let $C_n$ denote the cyclic group…

组合数学 · 数学 2025-01-31 Sanjay Mukherjee , Kamal Lochan Patra , Binod Kumar Sahoo

Let $G$ be a finite non-abelian group and ${\Gamma}_{nc}(G)$ be its non-commuting graph. In this paper, we compute spectrum and energy of ${\Gamma}_{nc}(G)$ for certain classes of finite groups. As a consequence of our results we construct…

群论 · 数学 2020-02-25 Walaa Nabil Taha Fasfous , Rajat Kanti Nath

The $d$-th order Laplacian spectral moment of a $k$-uniform hypergraph is the sum of the $d$-th powers of all eigenvalues of its Laplacian tensor. In this paper, we obtain some expressions of the Laplacian spectral moments for $k$-uniform…

组合数学 · 数学 2023-10-04 Jueru Liu , Lixiang Chen , Changjiang Bu

In this work, we define the Laplacian and Normalized Laplacian energies of vertices in a graph, we derive some of its properties and relate them to combinatorial, spectral and geometric quantities of the graph.

组合数学 · 数学 2022-01-05 José Guerrero

The energy of a graph $G$ is the sum of the absolute values of the eigenvalues of the adjacency matrix of $G$. Some variants of energy can also be found in the literature which are defined on the concepts of Laplacian matrix, Distance…

组合数学 · 数学 2026-04-27 Samir K. Vaidya , Kalpesh M. Popat

The power graph $\mathcal{P}(G)$ of a group $G$ is the simple graph with vertex set $G$ and two vertices are adjacent whenever one of them is a positive power of the other. In this paper, for a finite noncyclic nilpotent group $G$, we study…

组合数学 · 数学 2021-08-16 Ramesh Prasad Panda , Kamal Lochan Patra , Binod Kumar Sahoo

The energy of a graph is the sum of the moduli of the eigenvalues of its adjacency matrix. We study the energy of integral circulant graphs, also called gcd graphs, which can be characterized by their vertex count $n$ and a set $\cal D$ of…

组合数学 · 数学 2018-08-21 Jürgen W. Sander , Torsten Sander

Consider a group $\mathbb{G}$ and construct its power graph, whose vertex set consists of the elements of $\mathbb{G}$. Two distinct vertices (elements) are adjacent in the graph if and only if one element can be expressed as an integral…

谱理论 · 数学 2026-03-03 Priti Prasanna Mondal , Basit Auyoob Mir , Fouzul Atik

Let $G$ be a finite group. A number of graphs with the vertex set $G$ have been studied, including the power graph, enhanced power graph, and commuting graph. These graphs form a hierarchy under the inclusion of edge sets, and it is useful…

组合数学 · 数学 2021-12-07 G. Arunkumar , Peter J. Cameron , Rajat Kanti Nath , Lavanya Selvaganesh

Let $\Gamma=(V,E)$ be a graph. If all the eigenvalues of the adjacency matrix of the graph $\Gamma$ are integers, then we say that $\Gamma$ is an integral graph. A graph $\Gamma$ is determined by its spectrum if every graph cospectral to it…

组合数学 · 数学 2021-01-22 Jia-Bao Liu , S. Morteza Mirafzal , Ali Zafari

A signed graph is an ordered pair $\Sigma=(G,\sigma),$ where $G=(V,E)$ is the underlying graph of $\Sigma$ with a signature function $\sigma:E\rightarrow \{1,-1\}$. In this article, we define $n^{th}$ power of a signed graph and discuss…

组合数学 · 数学 2020-09-23 Shijin T , Germina K A , Shahul Hameed K

For a simple graph $G$ with $n$ vertices, let $A_G$ denote the adjacency matrix of $G$, and let $\lambda_1(G) \geq \lambda_2(G) \geq \dots \geq \lambda_n(G)$ be its eigenvalues. For an integer $p \geq 2$, the positive $p$-energy and…

组合数学 · 数学 2026-04-20 Zhengbo Chen , Zhouningxin Wang , Xiao-Dong Zhang

Let $H$ be a normal subgroup of a group $G$. The normal subgroup based power graph $\Gamma_H(G)$ of $G$ is the simple undirected graph with vertex set $V(\Gamma_H(G))= (G\setminus H)\cup \{e\}$ and two distinct vertices $a$ and $b$ are…

组合数学 · 数学 2024-04-08 Parveen , Manisha , Jitender Kumar

Given a regular (connected) graph $\Gamma=(X,E)$ with adjacency matrix $A$, $d+1$ distinct eigenvalues, and diameter $D$, we give a characterization of when its distance matrix $A_D$ is a polynomial in $A$, in terms of the adjacency…

组合数学 · 数学 2019-06-05 M. A. Fiol , Safet Penjić

Let $ G $ be a simple graph with the vertex cover number $ \tau $. The energy $ \mathcal{E}(G) $ of $ G $ is the sum of the absolute values of all the adjacency eigenvalues of $ G $. In this article, we establish $ \mathcal{E}(G)\geq 2\tau…

组合数学 · 数学 2025-07-02 Aniruddha Samanta

A complex unit gain graph is a graph where each orientation of an edge is given a complex unit, which is the inverse of the complex unit assigned to the opposite orientation. We extend some fundamental concepts from spectral graph theory to…

组合数学 · 数学 2014-08-26 Nathan Reff

Let ${G}$ be a finite non-abelian group. The non-commuting conjugacy class graph (abbreviated as NCCC-graph) of $G$ is a simple undirected graph whose vertex set is the set of conjugacy classes of non-central elements of $G$ and two…

组合数学 · 数学 2025-08-28 Rishabh Chakraborty , Firdous Ee Jannat , Rajat Kanti Nath

The $k$-th $p$-power of a graph $G$ is the graph on the vertex set $V(G)^k$, where two $k$-tuples are adjacent iff the number of their coordinates which are adjacent in $G$ is not congruent to 0 modulo $p$. The clique number of powers of…

组合数学 · 数学 2007-05-23 Noga Alon , Eyal Lubetzky