Results 61 to 70 of about 1,271 (139)
Construction of Albertson Cospectral and Albertson Equienergetic Graphs Using Graph Operations
Journal of Mathematics, Volume 2026, Issue 1, 2026.The energy of a graph is an invariant calculated as the sum of the absolute eigenvalues of its adjacency matrix. This concept extends to various types of energies derived from different graph‐related matrices. This paper explores the spectral properties of Albertson energy and Albertson spectra.
Jane Shonon Cutinha +3 more
wiley +1 more source
Sharp Bounds for the Signless Laplacian Spectral Radius in Terms of Clique Number [PDF]
, 2012 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.
Abraham Berman +5 more
core
Merging the A- and Q-spectral theories
, 2016 Let $G$ be a graph with adjacency matrix $A\left( G\right) $, and let $D\left( G\right) $ be the diagonal matrix of the degrees of $G.$ The signless Laplacian $Q\left( G\right) $ of $G$ is defined as $Q\left( G\right) :=A\left( G\right) +D\left( G\right)
Nikiforov, V.
core +1 more source
On maximum signless Laplacian Estrada index of graphs with given parameters II
Electronic Journal of Graph Theory and Applications, 2018 The signless Laplacian Estrada index of a graph G is defined as SLEE(G) = ∑ni = 1eqi where q1, q2, …, qn are the eigenvalues of the signless Laplacian matrix of G.
Ramin Nasiri +3 more
doaj +1 more source
The Extremal Structures of r-Uniform Unicyclic Hypergraphs on the Signless Laplacian Estrada Index
Mathematics, 2022 SLEE has various applications in a large variety of problems. The signless Laplacian Estrada index of a hypergraph H is defined as SLEE(H)=∑i=1neλi(Q), where λ1(Q),λ2(Q),…,λn(Q) are the eigenvalues of the signless Laplacian matrix of H. In this paper, we
Hongyan Lu, Zhongxun Zhu
doaj +1 more source
On the spectral radius of a class of non-odd-bipartite even uniform hypergraphs
, 2015 In order to investigate the non-odd-bipartiteness of even uniform hypergraphs, starting from a simple graph $G$, we construct a generalized power of $G$, denoted by $G^{k,s}$, which is obtained from $G$ by blowing up each vertex into a $k$-set and each ...
Fan, Yi-Zheng, Khan, Murad-ul-Islam
core +1 more source
Mathematische Nachrichten, Volume 297, Issue 5, Page 1749-1771, May 2024.Abstract Landscape functions are a popular tool used to provide upper bounds for eigenvectors of Schrödinger operators on domains. We review some known results obtained in the last 10 years, unify several approaches used to achieve such bounds, and extend their scope to a large class of linear and nonlinear operators. We also use landscape functions to
Delio Mugnolo
wiley +1 more source
Resistance Distance and Kirchhoff Index for a Class of Graphs
Mathematical Problems in Engineering, Volume 2018, Issue 1, 2018., 2018 Let G[F, Vk, Hv] be the graph with k pockets, where F is a simple graph of order n ≥ 1, Vk = {v1, v2, …, vk} is a subset of the vertex set of F, Hv is a simple graph of order m ≥ 2, and v is a specified vertex of Hv. Also let G[F, Ek, Huv] be the graph with k edge pockets, where F is a simple graph of order n ≥ 2, Ek = {e1, e2, …ek} is a subset of the ...
WanJun Yin +3 more
wiley +1 more source
Spectra of the neighbourhood corona of two graphs
, 2013 Given simple graphs $G_1$ and $G_2$, the neighbourhood corona of $G_1$ and $G_2$, denoted $G_1\star G_2$, is the graph obtained by taking one copy of $G_1$ and $|V(G_1)|$ copies of $G_2$, and joining the neighbours of the $i$th vertex of $G_1$ to every ...
Liu, Xiaogang, Zhou, Sanming
core +1 more source
Distance Spectra of Some Double Join Operations of Graphs
International Journal of Mathematics and Mathematical Sciences, Volume 2024, Issue 1, 2024.In literature, several types of join operations of two graphs based on subdivision graph, Q‐graph, R‐graph, and total graph have been introduced, and their spectral properties have been studied. In this paper, we introduce a new double join operation based on (H1, H2)‐merged subdivision graph.
B. J. Manjunatha +4 more
wiley +1 more source