Average Distance in Bipartite Tournaments

P. Dankelmann1, L. Volkmann2
1School of Mathematical and Statistical Sciences University of KwaZulu-Natal, Durban, South Africa
2Lehrstuhl II fiir Mathematik RWTH-Aachen, Germany

Abstract

The average distance \(\mu(D)\) of a strong digraph \(D\) is the average of the distances between all ordered pairs of distinct vertices of \(D\). Plesnik \([3]\) proved that if \(D\) is a strong tournament of order \(n\), then \(\mu(D) \leq \frac{n+4}{6} + \frac{1}{n}\). In this paper we show that, asymptotically, the same inequality holds for strong bipartite tournaments. We also give an improved upper bound on the average distance of a \(k\)-connected bipartite tournament.