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Related papers: Unicyclic Graphs with equal Laplacian Energy

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In this paper, we compute the Laplacian spectrum of non-commuting graphs of some classes of finite non-abelian groups. Our computations reveal that the non-commuting graphs of all the groups considered in this paper are L-integral. We also…

Group Theory · Mathematics 2017-05-04 Parama Dutta , Jutirekha Dutta , Rajat Kanti Nath

We propose the notion of normalized Laplacian matrix $\mathcal{L}(\Phi)$ for a gain graphs and study its properties in detail, providing insights and counterexamples along the way. We establish bounds for the eigenvalues of…

Combinatorics · Mathematics 2022-03-11 M. Rajesh Kannan , Navish Kumar , Shivaramakrishna Pragada

We give inequalities relating the eigenvalues of the adjacency matrix and the Laplacian of a graph, and its minimum and maximum degrees. The results are applied to derive new conditions for quasi-randomness of graphs.

Combinatorics · Mathematics 2007-05-23 Vladimir Nikiforov

We consider the class of simple graphs with large algebraic connectivity (the second-smallest eigenvalue of the Laplacian matrix). For this class of graphs we determine the asymptotic behavior of the number of Eulerian orientations. In…

Combinatorics · Mathematics 2013-06-10 Mikhail Isaev

In this note, we give an infinite family of optimal graphs called $G^+(d,c)$. They are optimal in the sense that they have the maximum possible number of vertices for given a diameter $d$ and the so-called `outer multiset dimension' $c$. We…

Combinatorics · Mathematics 2024-09-04 C. Dalfó , M. A. Fiol

In his survey "Beyond graph energy: Norms of graphs and matrices" (2016), Nikiforov proposed two problems concerning characterizing the graphs that attain equality in a lower bound and in a upper bound for the energy of a graph,…

Combinatorics · Mathematics 2020-10-06 N. E. Arévalo , R. O. Braga , V. M. Rodrigues

A sequence $D=(d_1,d_2,\ldots,d_n)$ of non-negative integers is called a graphic sequence if there is a simple graph with vertices $v_1,v_2,\ldots,v_n$ such that the degree of $v_i$ is $d_i$ for $1\leq i\leq n$. Given a graph theoretical…

Combinatorics · Mathematics 2025-04-23 Peiyi Duan , Yingzhi Tian

In this draft paper, we introduce a novel architecture for graph networks which is equivariant to the Euclidean group in $n$-dimensions. The model is designed to work with graph networks in their general form and can be shown to include…

Machine Learning · Computer Science 2021-05-24 Emma Slade , Francesco Farina

We present a novel spectral embedding of graphs that incorporates weights assigned to the nodes, quantifying their relative importance. This spectral embedding is based on the first eigenvectors of some properly normalized version of the…

Machine Learning · Computer Science 2018-10-04 Thomas Bonald , Alexandre Hollocou , Marc Lelarge

We extend the notions of the m-splitting graph Sm(G) and the m-shadow graph Dm(G) to introduce two new graph operations: the (p, q)-generalized splitting graph Sp,q(G) and the (c, k)-shadow-splitting graph Hc,k(G). We derive the adjacency…

Combinatorics · Mathematics 2026-04-02 Ronak B. Dudhat , Vinodray J. Kaneria , Kalpesh M. Popat

The characteristic polynomials of the Laplacian and the distance Laplacian matrices of power graphs of groups of order $ pqr $, where $ p,q $ and $ r $ are { primes,} are obtained. Further, the characteristic polynomials of these matrices…

Combinatorics · Mathematics 2026-04-21 Bilal Ahmad Rather , Mustapha Aouchiche , Victor A. Bovdi

A signless Laplacian eigenvalue of a graph $G$ is called a main signless Laplacian eigenvalue if it has an eigenvector the sum of whose entries is not equal to zero. In this paper, all connected bicyclic graphs with exactly two main…

Combinatorics · Mathematics 2013-10-10 He Huang , Hanyuan Deng

We establish metric graph counterparts of Pleijel's theorem on the asymptotics of the number of nodal domains $\nu_n$ of the $n$-th eigenfunction(s) of a broad class of operators on compact metric graphs, including Schr\"odinger operators…

Spectral Theory · Mathematics 2021-11-03 Matthias Hofmann , James B. Kennedy , Delio Mugnolo , Marvin Plümer

For a finite graph, we establish natural isomorphisms between eigenspaces of a Laplace operator acting on functions on the edges and eigenspaces of a transfer operator acting on functions on one-sided infinite non-backtracking paths.…

Spectral Theory · Mathematics 2023-12-15 Christian Arends , Jan Frahm , Joachim Hilgert

The energy of a graph is defined as the sum of the absolute values of the eigenvalues of its adjacency matrix. In this paper, we characterize the tetracyclic graph of order $n$ with minimal energy. By this, the validity of a conjecture for…

Combinatorics · Mathematics 2014-08-07 Hongping Ma , Yongqiang Bai

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…

Combinatorics · Mathematics 2026-04-27 Samir K. Vaidya , Kalpesh M. Popat

We investigate connections between the symmetries (automorphisms) of a graph and its spectral properties. Whenever a graph has a symmetry, i.e. a nontrivial automorphism $\phi$, it is possible to use $\phi$ to decompose any matrix…

Combinatorics · Mathematics 2016-10-07 Wayne Barrett , Amanda Francis , Ben Webb

In this note we give a new upper bound for the Laplacian eigenvalues of an unweighted graph. Let $G$ be a simple graph on $n$ vertices. Let $d_{m}(G)$ and $\lambda_{m+1}(G)$ be the $m$-th smallest degree of $G$ and the $m+1$-th smallest…

Combinatorics · Mathematics 2011-06-07 Miriam Farber , Ido Kaminer

Spectral analysis of networks states that many structural properties of graphs, such as centrality of their nodes, are given in terms of their adjacency matrices. The natural extension of such spectral analysis to higher order networks is…

Spectral Theory · Mathematics 2025-03-17 Gonzalo Contreras-Aso , Cristian Pérez-Corral , Miguel Romance

In this article we construct a series of new infinite families of strongly regular graphs with the same parameters as the point-graphs of non-singular quadrics in PG(n,2).

Combinatorics · Mathematics 2016-06-20 S. G. Barwick , Wen-Ai Jackson , Tim Penttila