316 search results - page 11 / 64 » The chromatic covering number of a graph |
JGT
2008
13 years 7 months ago
2008
: This article proves the following result: Let G and G be graphs of orders n and n , respectively. Let G be obtained from G by adding to each vertex a set of n degree 1 neighbors....
JGT
2008
13 years 7 months ago
2008
A homomorphism from an oriented graph G to an oriented graph H is a mapping from the set of vertices of G to the set of vertices of H such that ----(u)(v) is an arc in H whenever...
JGT
2007
13 years 7 months ago
2007
A cyclic colouring of a plane graph is a vertex colouring such that vertices incident with the same face have distinct colours. The minimum number of colours in a cyclic colouring...
FCT
2009
Springer
14 years 1 months ago
2009
Springer
We study the empire colouring problem (as defined by Percy Heawood in 1890) for maps whose dual planar graph is a tree, with empires formed by exactly r countries. We prove that, ...
ICALP
2007
Springer
14 years 1 months ago
2007
Springer
In this paper we consider the classical Erd˝os-R´enyi model of random graphs Gn,p. We show that for p = p(n) ≤ n−3/4−δ , for any fixed δ > 0, the chromatic number χ...