منابع مشابه
Graphs with Branchwidth at Most Three
In this paper we investigate both the structure of graphs with branchwidth at most three, as well as algorithms to recognise such graphs. We show that a graph has branchwidth at most three, if and only if it has treewidth at most three and does not contain the three-dimensional binary cube graph as a minor. A set of four graphs is shown to be the obstruction set of graphs with branchwidth at mo...
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 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 کاملRegular Projections of Graphs with at Most Three Double Points
We investigate some relations between a generic immersion of a graph into the 2-space with small number of double points and the embeddings of the graph into the 3-space obtained by lifting the immersion with respect to the natural projection from the 3-space to the 2-space. Specifically we prove: (1) An embedding of a graph obtained from a generic immersion of the graph with at most three doub...
متن کاملBranchwidth of chordal graphs
This paper revisits the ’branchwidth territories’ of Kloks, Kratochv́ıl and Müller [12] to provide a simpler proof and a faster algorithm for computing branchwidth of an interval graph. We also generalize the algorithm to the class of chordal graphs, albeit at the expense of exponential running time. Compliance with the ternary constraint of the branchwidth definition is facilitated by a simple ...
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: Journal of Algorithms
سال: 1999
ISSN: 0196-6774
DOI: 10.1006/jagm.1999.1011