Long cycles in bipartite tournaments
β Scribed by Jianzhong Wang
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 318 KB
- Volume
- 148
- Category
- Article
- ISSN
- 0012-365X
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β¦ Synopsis
A digraph D is said to satisfy the condition O(n) ifd~-(u) + d r (v) >t n whenever uv is not an arc of D. In this paper we prove the following results: If a p x q bipartite tournament T is strong and satisfies O(n), then T contains a cycle of length at least min(2n + 2, 2p, 2q}, unless T is isomorphic to a specified family of graphs. As an immediate consequence of this result we conclude that each arc of a n x n bipartite tournament satisfying O(n) is contained in cycles of lengths 4, 6 ..... 2n, except in a described case.
π SIMILAR VOLUMES
We consider a random rn by n bipartite tournament T, , consisting of rnn independent random arcs which have a common probability p of being directed from the rn part to the n part. We determine the expected value and variance of the number of 4-cycles in T,,,, and the probability that T, , has no cy
Let (x, y) be a specified arc in a k-regular bipartite tournament B. We prove that there exists a cycle C of length four through (x, y) in B such that B-C is hamiltonian.
We present a variety of results concerning characterization, number, distribution and some aspects of stability of r-kings (r = 2 4) of bipartite tournaments.