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Centers of n-fold tensor products of graphs

Sarah Bendall, Richard Hammack (2004)

Discussiones Mathematicae Graph Theory

Formulas for vertex eccentricity and radius for the n-fold tensor product G = i = 1 G i of n arbitrary simple graphs G i are derived. The center of G is characterized as the union of n+1 vertex sets of form V₁×V₂×...×Vₙ, with V i V ( G i ) .

Centralité et compacité d'un graphe

P. Parlebas (1972)

Mathématiques et Sciences Humaines

Un grand nombre de situations de psychologie sociale peuvent être interprétées en termes de graphe, notamment celles qui traitent des phénomènes de relation et de communication. Les travaux de A. Bavelas et H. Leavitt ont révélé l'influence des différents types de réseaux sur le comportement des groupes ; ils ont mis en pleine lumière l'intérêt de la notion de centralité. Les recherches de C. Flament ont enrichi et fortement nuancé ces résultats en faisant apparaître le poids de la nature de la...

Centrosymmetric Graphs And A Lower Bound For Graph Energy Of Fullerenes

Gyula Y. Katona, Morteza Faghani, Ali Reza Ashrafi (2014)

Discussiones Mathematicae Graph Theory

The energy of a molecular graph G is defined as the summation of the absolute values of the eigenvalues of adjacency matrix of a graph G. In this paper, an infinite class of fullerene graphs with 10n vertices, n ≥ 2, is considered. By proving centrosymmetricity of the adjacency matrix of these fullerene graphs, a lower bound for its energy is given. Our method is general and can be extended to other class of fullerene graphs.

Certain new M-matrices and their properties with applications

Ratnakaram N. Mohan, Sanpei Kageyama, Moon H. Lee, G. Yang (2008)

Discussiones Mathematicae Probability and Statistics

The Mₙ-matrix was defined by Mohan [21] who has shown a method of constructing (1,-1)-matrices and studied some of their properties. The (1,-1)-matrices were constructed and studied by Cohn [6], Ehrlich [9], Ehrlich and Zeller [10], and Wang [34]. But in this paper, while giving some resemblances of this matrix with a Hadamard matrix, and by naming it as an M-matrix, we show how to construct partially balanced incomplete block designs and some regular graphs by it. Two types of these M-matrices...

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