Fast Lower Bounds for the Capacitated Minimum Spanning Tree Problem

We propose some techniques, based on minimum cost flow computations, for efficiently computing lower bounds for the Capacitated Minimum Spanning Tree problem (CMST). With respect to other methods proposed in the literature, our approaches often provide comparable bounds, with a substantially lower computational cost. For this reason, and for other features discussed in the paper, the proposed methods may be particularly promising in the context of exact algorithms for CMST.