Results 71 to 80 of about 2,530 (150)

On Almost Distance-Regular Graphs [PDF]

2010 Mathematics Subject Classification: 05E30, 05C50;distance-regular graph;walk-regular graph;eigenvalues;predistance ...
Dalfo, C., Dam, E.R. van, Fiol, M.A., Garriga, E., Gorissen, B.L.   +4 more
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Signed graphs with strong (anti-)reciprocal eigenvalue property

Special Matrices
A (signed) graph is said to exhibit the strong reciprocal (anti-reciprocal) eigenvalue property (SR) (resp., (-SR)) if for any eigenvalue λ\lambda , it has 1λ\frac{1}{\lambda } (resp.,−1λ-\frac{1}{\lambda }) as an eigenvalue as well, with the same ...
Belardo Francesco, Huntington Callum
doaj   +1 more source

Divisible Design Graphs [PDF]

AMS Subject Classification: 05B05, 05E30, 05C50.Strongly regular graph;Group divisible design;Deza graph;(v;k ...
Haemers, W.H., Kharaghani, H., Meulenberg, M.A.   +2 more
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On the Laplacian index of tadpole graphs

Special Matrices
In this article, we study the Laplacian index of tadpole graphs, which are unicyclic graphs formed by adding an edge between a cycle Ck{C}_{k} and a path Pn{P}_{n}.
Braga Rodrigo O., Veloso Bruno S.
doaj   +1 more source

Asymptotic Results on the Spectral Radius and the Diameter of Graphs [PDF]

2000 Mathematics Subject Classification: 05C50, 05E99;graphs;spectral radius;diameter;limit points ...
Cioaba, S.M., Dam, E.R. van, Koolen, J.H., Lee, J.H.   +3 more
core   +1 more source

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

Special 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

An Odd Characterization of the Generalized Odd Graphs [PDF]

2010 Mathematics Subject Classification: 05E30, 05C50;distance-regular graphs;generalized odd graphs;odd-girth;spectra of graphs;spectral excess theorem;spectral ...
Dam, E.R. van, Haemers, W.H.
core   +1 more source

Some results involving the Aα-eigenvalues for graphs and line graphs

Special Matrices
Let GG be a simple graph with adjacency matrix A(G)A\left(G), degree diagonal matrix D(G),D\left(G), and let l(G)l\left(G) be the line graph of GG. In 2017, Nikiforov defined the Aα{A}_{\alpha }-matrix of GG, Aα(G){A}_{\alpha }\left(G), as a linear ...
da Silva Júnior João Domingos G., Oliveira Carla Silva, da Costa Liliana Manuela G. C.   +2 more
doaj   +1 more source

Universal Adjacency Matrices with Two Eigenvalues [PDF]

AMS Mathematics Subject Classification: 05C50.Adjacency matrix;Universal adjacency matrix;Laplacian matrix;signless Laplacian;Graph spectra;Eigenvalues;Strongly regular ...
Haemers, W.H., Omidi, G.R.
core   +1 more source

Signless Laplacian characterization of cones over disjoint unions of cycles, edges and isolated vertices

Special Matrices
Two graphs are said to be Q-cospectral if they share the same signless Laplacian spectrum. A simple graph is said to be determined by its signless Laplacian spectrum (abbreviated as DQS) if there exists no other non-isomorphic simple graph with the same ...
Ye Jiachang, Qian Jianguo, Stanić Zoran
doaj   +1 more source