Results 21 to 30 of about 858 (123)
Two Kinds of Laplacian Spectra and Degree Kirchhoff Index of the Weighted Corona Networks
Journal 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
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New bounds for the spread of the signless Laplacian spectrum [PDF]
Mathematical Inequalities & Applications, 2014 The spread of the singless Laplacian of a simple graph G is defined as SQ(G) = μ1(G)− μn(G) , where μ1(G) and μn(G) are the maximum and minimum eigenvalues of the signless Laplacian matrix of G , respectively. In this paper, we will present some new lower and upper bounds for SQ(G) in terms of clique and independence numbers.
Guengoer, A. Dilek Maden +2 more
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New Bounds for the Generalized Distance Spectral Radius/Energy of Graphs
Mathematical 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
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Spectral properties of the commuting graphs of certain groups
AKCE International Journal of Graphs and Combinatorics, 2019 Let G be a finite group. The commuting graph Γ=C(G)is a simple graph with vertex set G and two vertices are adjacent if and only if they commute with each other.
M. Torktaz, A.R. Ashrafi
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On Laplacian Equienergetic Signed Graphs
Journal 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
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Sufficient Conditions for Graphs to Be k‐Connected, Maximally Connected, and Super‐Connected
Complexity, 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
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Locating Eigenvalues of a Symmetric Matrix whose Graph is Unicyclic
Trends in Computational and Applied Mathematics, 2021 We present a linear-time algorithm that computes in a given real interval the number of eigenvalues of any symmetric matrix whose underlying graph is unicyclic.
R. O. Braga +2 more
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Hamilton Connectivity of Convex Polytopes with Applications to Their Detour Index
Complexity, Volume 2021, Issue 1, 2021., 2021 A connected graph is called Hamilton‐connected if there exists a Hamiltonian path between any pair of its vertices. Determining whether a graph is Hamilton‐connected is an NP‐complete problem. Hamiltonian and Hamilton‐connected graphs have diverse applications in computer science and electrical engineering.
Sakander Hayat +4 more
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Theory and Applications of Graphs, 2021 In this article, we introduce the concept of nilpotent graph of a finite commutative ring. The set of all non nilpotent elements of a ring is taken as the vertex set and two vertices are adjacent if and only if their sum is nilpotent.
Dhiren Basnet, Ajay Sharma, Rahul Dutta
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Journal of Mathematics, Volume 2021, Issue 1, 2021., 2021 Let G be a graph with n vertices, and let L(G) and Q(G) denote the Laplacian matrix and signless Laplacian matrix, respectively. The Laplacian (respectively, signless Laplacian) permanental polynomial of G is defined as the permanent of the characteristic matrix of L(G) (respectively, Q(G)).
Tingzeng Wu +2 more
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