Results 31 to 40 of about 63,846 (213)

The gamma-Signless Laplacian Adjacency Matrix of Mixed Graphs

open access: yesTheory and Applications of Graphs, 2023
The α-Hermitian adjacency matrix Hα of a mixed graph X has been recently introduced. It is a generalization of the adjacency matrix of unoriented graphs. In this paper, we consider a special case of the complex number α.
Omar Alomari   +2 more
doaj   +1 more source

The normalized signless laplacian estrada index of graphs [PDF]

open access: yesTransactions on Combinatorics, 2023
Let $G$ be a simple connected graph of order $n$ with $m$ edges. Denote by $% \gamma _{1}^{+}\geq \gamma _{2}^{+}\geq \cdots \geq \gamma _{n}^{+}\geq 0$ the normalized signless Laplacian eigenvalues of $G$. In this work, we define the normalized signless
Ş. Burcu Bozkurt Altındağ   +3 more
doaj   +1 more source

On Extremal Spectral Radii of Uniform Supertrees with Given Independence Number

open access: yesDiscrete Dynamics in Nature and Society, Volume 2022, Issue 1, 2022., 2022
A supertree is a connected and acyclic hypergraph. Denote by Tm,n,α the set of m‐uniform supertrees of order n with independent number α. Focusing on the spectral radius in Tm,n,α, this present completely determines the hypergraphs with maximum spectral radius among all the supertrees with n vertices and independence number α for [m − 1/mn] ≤ α ≤ n − 1,
Lei Zhang   +2 more
wiley   +1 more source

Two Kinds of Laplacian Spectra and Degree Kirchhoff Index of the Weighted Corona Networks

open access: yesJournal of Mathematics, Volume 2022, Issue 1, 2022., 2022
Recently, the study related to network has aroused wide attention of the scientific community. Many problems can be usefully represented by corona graphs or networks. Meanwhile, the weight is a vital factor in characterizing some properties of real networks.
Haiqin Liu, Yanling Shao, Azhar Hussain
wiley   +1 more source

New Bounds for the Generalized Distance Spectral Radius/Energy of Graphs

open access: yesMathematical Problems in Engineering, Volume 2022, Issue 1, 2022., 2022
Let G be a simple connected graph with vertex set V(G) = {v1, v2, …, vn} and dvi be the degree of the vertex vi. Let D(G) be the distance matrix and Tr(G) be the diagonal matrix of the vertex transmissions of G. The generalized distance matrix of G is defined as Dα(G) = αTr(G) + (1 − α)D(G), where 0 ≤ α ≤ 1. If λ1, λ2, …, λn are the eigenvalues of Dα(G)
Yuzheng Ma   +3 more
wiley   +1 more source

Spectral Sufficient Conditions on Pancyclic Graphs

open access: yesComplexity, Volume 2021, Issue 1, 2021., 2021
A pancyclic graph of order n is a graph with cycles of all possible lengths from 3 to n. In fact, it is NP‐complete that deciding whether a graph is pancyclic. Because the spectrum of graphs is convenient to be calculated, in this study, we try to use the spectral theory of graphs to study this problem and give some sufficient conditions for a graph to
Guidong Yu   +4 more
wiley   +1 more source

The Signless Laplacian Estrada Index of Unicyclic Graphs [PDF]

open access: yesMathematics Interdisciplinary Research, 2017
‎For a simple graph G‎, ‎the signless Laplacian Estrada index is defined as SLEE(G)=∑ni=1eqi‎, ‎where q1‎, ‎q2‎,...‎, ‎qn are the eigenvalues of the signless Laplacian matrix of G‎.
Hamid Reza Ellahi   +3 more
doaj   +1 more source

On Zagreb index, signless Laplacian eigenvalues and signless Laplacian energy of a graph

open access: yesComputational and Applied Mathematics, 2023
13
S. Pirzada, Saleem Khan
openaire   +2 more sources

On Laplacian Equienergetic Signed Graphs

open access: yesJournal of Mathematics, Volume 2021, Issue 1, 2021., 2021
The Laplacian energy of a signed graph is defined as the sum of the distance of its Laplacian eigenvalues from its average degree. Two signed graphs of the same order are said to be Laplacian equienergetic if their Laplacian energies are equal. In this paper, we present several infinite families of Laplacian equienergetic signed graphs.
Qingyun Tao, Lixin Tao, Yongqiang Fu
wiley   +1 more source

Sufficient Conditions for Graphs to Be k‐Connected, Maximally Connected, and Super‐Connected

open access: yesComplexity, Volume 2021, Issue 1, 2021., 2021
Let G be a connected graph with minimum degree δ(G) and vertex‐connectivity κ(G). The graph G is k‐connected if κ(G) ≥ k, maximally connected if κ(G) = δ(G), and super‐connected if every minimum vertex‐cut isolates a vertex of minimum degree. In this paper, we present sufficient conditions for a graph with given minimum degree to be k‐connected ...
Zhen-Mu Hong   +4 more
wiley   +1 more source

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