منابع مشابه
0 On bipartite graphs of defect at most 4 Ramiro
We consider the bipartite version of the degree/diameter problem, namely, given natural numbers ∆ ≥ 2 and D ≥ 2, find the maximum number Nb(∆,D) of vertices in a bipartite graph of maximum degree ∆ and diameter D. In this context, the Moore bipartite bound Mb(∆,D) represents an upper bound for Nb(∆,D). Bipartite graphs of maximum degree ∆, diameter D and order Mb(∆,D), called Moore bipartite gr...
متن کاملct 2 01 0 On graphs of defect at most 2
In this paper we consider the degree/diameter problem, namely, given natural numbers ∆ ≥ 2 and D ≥ 1, find the maximum number N(∆,D) of vertices in a graph of maximum degree ∆ and diameter D. In this context, the Moore bound M(∆,D) represents an upper bound for N(∆,D). Graphs of maximum degree ∆, diameter D and order M(∆,D), called Moore graphs, turned out to be very rare. Therefore, it is very...
متن کاملCOSPECTRALITY MEASURES OF GRAPHS WITH AT MOST SIX VERTICES
Cospectrality of two graphs measures the differences between the ordered spectrum of these graphs in various ways. Actually, the origin of this concept came back to Richard Brualdi's problems that are proposed in cite{braldi}: Let $G_n$ and $G'_n$ be two nonisomorphic simple graphs on $n$ vertices with spectra$$lambda_1 geq lambda_2 geq cdots geq lambda_n ;;;text{and};;; lambda'_1 geq lambda'_2...
متن کاملChromaticity of Turan Graphs with At Most Three Edges Deleted
Let $P(G,lambda)$ be the chromatic polynomial of a graph $G$. A graph $G$ ischromatically unique if for any graph $H$, $P(H, lambda) = P(G,lambda)$ implies $H$ is isomorphic to $G$. In this paper, we determine the chromaticity of all Tur'{a}n graphs with at most three edges deleted. As a by product, we found many families of chromatically unique graphs and chromatic equivalence classes of graph...
متن کاملOn bipartite graphs of defect 2
It is known that the Moore bipartite bound provides an upper bound on the order of a connected bipartite graph. In this paper we deal with bipartite graphs of maximum degree ∆ ≥ 2, diameter D ≥ 2 and defect 2 (having 2 vertices less than the Moore bipartite bound). We call such graphs bipartite (∆, D,−2)-graphs. We find that the eigenvalues other than ±∆ of such graphs are the roots of the poly...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 2011
ISSN: 0166-218X
DOI: 10.1016/j.dam.2011.04.018