Results 31 to 40 of about 858 (123)
Cospectral constructions for several graph matrices using cousin vertices
Special Matrices, 2021 Graphs can be associated with a matrix according to some rule and we can find the spectrum of a graph with respect to that matrix. Two graphs are cospectral if they have the same spectrum.
Lorenzen Kate
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Signless Laplacian determinations of some graphs with independent edges
Karpatsʹkì Matematičnì Publìkacìï, 2018 Let $G$ be a simple undirected graph. Then the signless Laplacian matrix of $G$ is defined as $D_G + A_G$ in which $D_G$ and $A_G$ denote the degree matrix and the adjacency matrix of $G$, respectively.
R. Sharafdini, A.Z. Abdian
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A novel method to construct cospectral graphs based on RT operation [PDF]
AIP AdvancesThis paper presents a new graph operation, RT(G), which is formed by transforming each vertex and edge of the original graph G into a triangle. We analyze the relationship between the signless Laplacian characteristic polynomials of the graph RT(G) and ...
Xiu-Jian Wang +2 more
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Color signless Laplacian energy of graphs
AKCE 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
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On the construction of L-equienergetic graphs
AKCE 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
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On the sum of signless Laplacian spectra of graphs
Karpatsʹkì Matematičnì Publìkacìï, 2019 For a simple graph $G(V,E)$ with $n$ vertices, $m$ edges, vertex set $V(G)=\{v_1, v_2, \dots, v_n\}$ and edge set $E(G)=\{e_1, e_2,\dots, e_m\}$, the adjacency matrix $A=(a_{ij})$ of $G$ is a $(0, 1)$-square matrix of order $n$ whose $(i,j)$-entry is ...
S. Pirzada, H.A. Ganie, A.M. Alghamdi
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The sun graph is determined by its signless Laplacian spectrum [PDF]
The Electronic Journal of Linear Algebra, 2010 For a simple undirected graph G, the corresponding signless Laplacian matrix is defined as D(G) + A(G) in which D(G) and A(G) are degree matrix and adjacency matrix of G, respectively. The graph G is said to be determined by its signless Laplacian spectrum, if any graph having the same signless Laplacian spectrum as G is isomorphic to G.
Maryam Mirzakhah, Dariush Kiani
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Topological Indices of Certain Transformed Chemical Structures
Journal of Chemistry, Volume 2020, Issue 1, 2020., 2020 Topological indices like generalized Randić index, augmented Zagreb index, geometric arithmetic index, harmonic index, product connectivity index, general sum‐connectivity index, and atom‐bond connectivity index are employed to calculate the bioactivity of chemicals.
Xuewu Zuo +5 more
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A Note on Some Bounds of the α‐Estrada Index of Graphs
Advances in Mathematical Physics, Volume 2020, Issue 1, 2020., 2020 Let G be a simple graph with n vertices. Let A~αG=αDG+1−αAG, where 0 ≤ α ≤ 1 and A(G) and D(G) denote the adjacency matrix and degree matrix of G, respectively. EEαG=∑i=1neλi is called the α‐Estrada index of G, where λ1, ⋯, λn denote the eigenvalues of A~αG. In this paper, the upper and lower bounds for EEα(G) are given.
Yang Yang +3 more
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Construction for the Sequences of Q‐Borderenergetic Graphs
Mathematical Problems in Engineering, Volume 2020, Issue 1, 2020., 2020 This research intends to construct a signless Laplacian spectrum of the complement of any k‐regular graph G with order n. Through application of the join of two arbitrary graphs, a new class of Q‐borderenergetic graphs is determined with proof. As indicated in the research, with a regular Q‐borderenergetic graph, sequences of regular Q‐borderenergetic ...
Bo Deng +4 more
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