On mixed almost Moore graphs of diameter two
Data de publicació2016-04-01
MetadadesMostra el registre d'unitat complet
Mixed almost Moore graphs appear in the context of the Degree/Diameter problem as a class of extremal mixed graphs, in the sense that their order is one less than the Moore bound for mixed graphs. The problem of their existence has been considered before for directed graphs and undirected ones, but not for the mixed case, which is a kind of generalization. In this paper we give some necessary conditions for the existence of mixed almost Moore graphs of diameter two derived from the factorization in Q[x] of their characteristic polynomial. In this context, we deal with the irreducibility of Φi(x2+x−(r−1)), where Φi(x) denotes the i-th cyclotomic polynomial.
És part deElectronic Journal of Combinatorics, 2016, vol. 23, num. 2, p. 1-14
Projectes de recerca europeus
Mostrant elements relacionats per títol, autor i matèria.
López Lorenzo, Ignacio; Pérez Rosés, Hebert; Pujolàs Boix, Jordi (Elsevier, 2017-11-20)This paper investigates the upper bounds for the number of vertices in mixed abelian Cayley graphs with given degree and diameter. Additionally, in the case when the undirected degree is equal to one, we give a construction ...
Buset, Dominique; López Lorenzo, Ignacio; Miret, Josep M. (Josep Maria) (World Scientific Publishing, 2017-11-02)A natural upper bound for the maximum number of vertices in a mixed graph with maximum undirected degree r, maximum directed out-degree z and diameter k is given by the mixed Moore bound. Graphs with order attaining the ...
López Lorenzo, Ignacio; Pérez Rosés, Hebert (Elsevier, 2015)The Degree/diameter problem asks for the largest graphs given diameter and maximum degree. This problem has been extensively studied both for directed and undirected graphs, ando also for special classes of graphs. In this ...