## Abstract In this article, we shall prove that every bipartite quadrangulation __G__ on the torus admits a simple closed curve visiting each face and each vertex of __G__ exactly once but crossing no edge. As an application, we conclude that the radial graph of any bipartite quadrangulation on th
On 4-cycles in random bipartite tournaments
✍ Scribed by Béla Bollobés; Ove Frank; Michał KarońSki
- Publisher
- John Wiley and Sons
- Year
- 1983
- Tongue
- English
- Weight
- 413 KB
- Volume
- 7
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
✦ Synopsis
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 cycles. An asymptotic expression for this probability is also given when p = f and rn and n tend to infinity.
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## Abstract Let __p__ and __C__~4~ (__G__) be the number of vertices and the number of 4‐cycles of a maximal planar graph __G__, respectively. Hakimi and Schmeichel characterized those graphs __G__ for which __C__~4~ (__G__) = 1/2(__p__^2^ + 3__p__ ‐ 22). This characterization is correct if __p__ ≥