A 1-factorisation of a graph is perfect if the union of any two of its 1-factors is a Hamiltonian cycle. Let n=p 2 for an odd prime p. We construct a family of ( p -1)/2 non-isomorphic perfect 1-factorisations of K n, n . Equivalently, we construct pan-Hamiltonian Latin squares of order n. A Latin s
Complete bipartite factorisations by complete bipartite graphs
โ Scribed by N. Martin
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 887 KB
- Volume
- 167-168
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
We study complete Kp,q-factorisations of Kin, n, Simple necessary conditions are found and we conjecture that these conditions are also sufficient. A general construction is given to find infinite families of factorisations proving the conjecture in many cases. The conjecture is proved for Kl,q-factorisations of Kn, n except for q = 4k + 1. The conjecture is also proved for a further family of Kl, 3-factorisations.
๐ SIMILAR VOLUMES
For two integers a and b, we say that a bipartite graph G admits an (a, b)bipartition if G has a bipartition (X, Y ) such that |X| = a and |Y | = b. We say that two bipartite graphs G and H are compatible if, for some integers a and b, both G and H admit (a, b)-bipartitions. In this paper, we prove
For every positive integer r there exists a constant C r depending only on r such that for every colouring of the edges of the complete bipartite graph K n, n with r colours, there exists a set of at most C r monochromatic cycles whose vertex sets partition the vertex set of K n, n . This answers a
## Abstract Given a graph __G__, for each ฯ โ__V__(__G__) let __L__(ฯ ) be a list assignment to __G__. The wellโknown choice number __c__(__G__) is the least integer __j__ such that if |__L__(ฯ )| โฅ__j__ for all ฯ โ__V__(__G__), then __G__ has a proper vertex colouring ฯ with ฯ(ฯ ) โ __L__ (ฯ ) (โฯ โ__
For a complete bipartite graph, the number of dependent edges in an acyclic orientation can be any integer from n-1 to e, where n and e are the number of vertices and edges in the graph. ## Ke3,words: Bipartite graph; Acyclic orientation Ill combinatorics we often ask whether an integer parameter