Results 41 to 50 of about 292 (163)
A Lower Bound for the Spectral Radius of Graphs with Fixed Diameter [PDF]
, 2008 AMS classifications: 05C50 ...
Koolen, J.H. +3 more
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On the α-Spectral Radius of Uniform Hypergraphs
Discussiones Mathematicae Graph Theory, 2020 For 0 ≤ α ---lt--- 1 and a uniform hypergraph G, the α-spectral radius of G is the largest H-eigenvalue of αD(G)+(1−α)A(G), where D(G) and A(G) are the diagonal tensor of degrees and the adjacency tensor of G, respectively. We give upper bounds for the α-
Guo Haiyan, Zhou Bo
doaj +1 more source
On the Eccentric Spectra of the Line Graph of Starlike Trees
Discrete Dynamics in Nature and Society, Volume 2025, Issue 1, 2025.A tree is called starlike if it has exactly one vertex with a degree greater than two. In this paper, we determine the eccentricity spectrum of the line graphs of starlike trees and compute their eccentric energy. Furthermore, we establish that the eccentricity matrix of the line graph of any starlike tree is irreducible.
S. Balamoorthy +4 more
wiley +1 more source
Eigenvalue bracketing for discrete and metric graphs [PDF]
, 2008 28 pages, 6 figures.-- MSC2000 codes: 05C50, 05C70, 47A10.-- ArXiv pre-print available at: http://arxiv.org/abs/0804.1076MR#: MR2446037 (2010a:47076)Zbl#: Zbl 1152.05044We develop eigenvalue estimates for the Laplacians on discrete and metric graphs ...
Post, Olaf +4 more
core +1 more source
On the Distance Spectral Radius of Trees with Given Degree Sequence
Discussiones Mathematicae Graph Theory, 2020 We consider the problem of maximizing the distance spectral radius and a slight generalization thereof among all trees with some prescribed degree sequence.
Dadedzi Kenneth +2 more
doaj +1 more source
Prime Graphs of Polynomials and Power Series Over Noncommutative Rings
International Journal of Mathematics and Mathematical Sciences, Volume 2025, Issue 1, 2025.The prime graph PG(R) of a ring R is a graph whose vertex set consists of all elements of R. Two elements x, y ∈ R are adjacent in the graph if and only if xRy = 0 or yRx = 0. An element a ∈ R is called a strong zero divisor in R if 〈a〉〈b〉 = 0 or 〈b〉〈a〉 = 0 for some nonzero element b ∈ R. The set of all strong zero divisors is denoted by S(R).
Walaa Obaidallah Alqarafi +3 more
wiley +1 more source
On the Displacement of Eigenvalues When Removing a Twin Vertex
Discussiones Mathematicae Graph Theory, 2020 Twin vertices of a graph have the same open neighbourhood. If they are not adjacent, then they are called duplicates and contribute the eigenvalue zero to the adjacency matrix.
Briffa Johann A., Sciriha Irene
doaj +1 more source
On the Maximum SC Index of Chemical Unicyclic Graphs
Journal of Mathematics, Volume 2025, Issue 1, 2025.The sum‐connectivity (SC) index of a graph G is defined as SCG=∑μν∈EG1/Θμ+Θν, where Θμ denotes the vertex degree of μ in G. In this paper, the fourth largest value of SC index for the chemical unicyclic graphs of order n ≥ 7 is determined.
Hui-Yan Cheng +3 more
wiley +1 more source
The Number of P-Vertices of Singular Acyclic Matrices: An Inverse Problem
Discussiones Mathematicae Graph Theory, 2020 Let A be a real symmetric matrix. If after we delete a row and a column of the same index, the nullity increases by one, we call that index a P-vertex of A.
Du Zhibin, da Fonseca Carlos M.
doaj +1 more source
Uniformity in association schemes and coherent configurations: cometric Q-antipodal schemes and linked systems [PDF]
, 2010 2010 Mathematics Subject Classification.
Edwin R. Van Dam +5 more
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