Oriented hypergraphs, stability numbers and chromatic numbers
نویسندگان
چکیده
منابع مشابه
The chromatic numbers of random hypergraphs
For a pair of integers 1Fgr, the g-chromatic number of an r-uniform Ž . hypergraph Hs V, E is the minimal k, for which there exists a partition of V into subsets < < T , . . . , T such that elT Fg for every egE. In this paper we determine the asymptotic 1 k i Ž . behavior of the g-chromatic number of the random r-uniform hypergraph H n, p for all r Ž yrq1. possible values of g and for all value...
متن کاملStrong total chromatic numbers of complete hypergraphs
We determine the strong total chromatic number of the complete h-uniform hypergraph Kh, and the complete h-partite hypergraph K,
متن کاملAcyclic and oriented chromatic numbers of graphs
The oriented chromatic number χo(~ G) of an oriented graph ~ G = (V,A) is the minimum number of vertices in an oriented graph ~ H for which there exists a homomorphism of ~ G to ~ H. The oriented chromatic number χo(G) of an undirected graph G is the maximum of the oriented chromatic numbers of all the orientations of G. This paper discusses the relation between the oriented chromatic number an...
متن کاملStar chromatic numbers of hypergraphs and partial Steiner triple systems
The concept of star chromatic number of a graph, introduced by Vince (1988) is a natural generalization of the chromatic number of a graph. This concept was studied from a pure combinatorial point of view by Bondy and Hell (1990). In this paper we introduce strong and weak star chromatic numbers of uniform hypergraphs and study their basic properties. In particular, we focus on partial Steiner ...
متن کاملChromatic Numbers of Directed Hypergraphs with No “bad” Cycles
Definition 1. A directed hypergraph of uniformity k is a pair (V,E) with E ⊆ V k. The chromatic number of a directed hypergraph is the chromatic number of the associated undirected hypergraph, that is, the least number χ such that there exists a function f : V → [χ] such that for each edge e ∈ E, not all of f(e1), ..., f(ek) are equal. We’ll assume that no edge of E has any two coordinates equa...
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 Mathematics
سال: 1981
ISSN: 0012-365X
DOI: 10.1016/0012-365x(81)90011-x