Random matching problems on the complete graph

Abstract

The edges of the complete graph on $n$ vertices are assigned independent exponentially distributed costs. A $k$-matching is a set of $k$ edges of which no two have a vertex in common. We obtain explicit bounds on the expected value of the minimum total cost $C_{k,n}$ of a $k$-matching. In particular we prove that if $n = 2k$ then $\pi^2/12 < EC_{k,n} < \pi^2/12 + \log n/n$.