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Laplacian energy and first Zagreb index of Laplacian integral graphs

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2022
The set Si,n = {0, 1, 2, …, i − 1, i + 1, …, n − 1, n}, 1 ⩽ i ⩽ n, is called Laplacian realizable if there exists a simple connected undirected graph whose Laplacian spectrum is Si,n. The existence of such graphs was established by S. Fallat et all.
Hameed Abdul   +2 more
doaj   +1 more source

On the construction of L-equienergetic graphs

open access: yesAKCE International Journal of Graphs and Combinatorics, 2015
For a graph G with n vertices and m edges, and having Laplacian spectrum μ1,μ2,…,μn and signless Laplacian spectrum μ1+,μ2+,…,μn+, the Laplacian energy and signless Laplacian energy of G are respectively, defined as LE(G)=∑i=1n|μi−2mn| and LE+(G)=∑i=1n ...
S. Pirzada, Hilal A. Ganie
doaj   +1 more source

Chirality-driven all-optical image differentiation

open access: yesNanophotonics
Optical analog computing enables powerful functionalities, including spatial differentiation, image processing, and ultrafast linear operations. Yet, most existing approaches rely on resonant or periodic structures, whose performance is strongly ...
Koufidis Stefanos Fr.   +4 more
doaj   +1 more source

An Interpretation of the Geometric Meaning of the Finite Difference and the Function Derivative through the Use of the Finite Element Method Tools

open access: yesМеханика машин, механизмов и материалов, 2016
In the present article on the basis of earlier formulated planspatial problem of the finite elements method the concept of finite differences for the twodimensional continuous environment is developed.
Hrant A. Gevorgyan
doaj  

Normalized Laplacian spectrum of some subdivision-joins and R-joins of two regular graphs

open access: yesAKCE International Journal of Graphs and Combinatorics, 2018
In this paper we determine the full normalized Laplacian spectrum of the subdivision-vertex join, subdivision-edge join, R-vertex join, and R-edge join of two regular graphs in terms of the normalized Laplacian eigenvalues of the graphs.
Arpita Das, Pratima Panigrahi
doaj   +1 more source

The Laplacian spectrum of weighted composite networks and the applications

open access: yesAIP Advances
The topological properties of the networks can be described by the Laplacian spectra, but resolving the Laplacian spectra of networks poses difficulties. In this study, a novel approach for solving the Laplacian spectrum of weighted composite networks is
Jian Zhu   +3 more
doaj   +1 more source

New constructions of nonregular cospectral graphs

open access: yesSpecial Matrices
We consider two types of joins of graphs G1{G}_{1} and G2{G}_{2}, G1⊻G2{G}_{1}\hspace{0.33em}⊻\hspace{0.33em}{G}_{2} – the neighbors splitting join and G1∨=G2{G}_{1}\mathop{\vee }\limits_{=}{G}_{2} – the nonneighbors splitting join, and compute ...
Hamud Suleiman, Berman Abraham
doaj   +1 more source

Color signless Laplacian energy of graphs

open access: yesAKCE International Journal of Graphs and Combinatorics, 2017
In this paper, we introduce the new concept of color Signless Laplacian energy . It depends on the underlying graph and the colors of the vertices. Moreover, we compute color signless Laplacian spectrum and the color signless Laplacian energy of families
Pradeep G. Bhat, Sabitha D’Souza
doaj   +1 more source

What is a proper graph Laplacian? An operator-theoretic framework for graph diffusion

open access: yesSpecial Matrices
We introduce an operator-theoretic definition of a proper graph Laplacian as any matrix associated with a given graph that can be expressed as the composition of a divergence and a gradient operator, with the gradient acting between graph-related spaces ...
Estrada Ernesto
doaj   +1 more source

Oscillatory Property of Solutions for p(t)-Laplacian Equations

open access: yesJournal of Inequalities and Applications, 2007
We consider the oscillatory property of the following p(t)-Laplacian equations −(|u'|p(t)−2u')'=1/tθ(t)g(t,u), t>0. Since there is no Picone-type identity for p(t)- Laplacian equations, it is an unsolved problem that whether the Sturmian ...
Qihu Zhang
doaj   +1 more source

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