On the existence of shortest directed networks
Abstract
A directed network connecting a set A to a set B is a digraph containing an a-b path for each a in A and b in B. Vertices in the directed network not in A or B are called Steiner points. We show that in a finitely compact metric space in which geodesics exist, any two finite sets A and B are connected by a shortest directed network. We also bound the number of Steiner points by a function of the sizes of A and B. Previously, such an existence result was known only for the Euclidean plane [M. Alfaro, Pacific J. Math. 167 (1995) 201-214]. The main difficulty is that, unlike the undirected case (Steiner minimal trees), the underlying graphs need not be acyclic. Existence in the undirected case was first shown by E. J. Cockayne [Canad. Math. Bull. 10 (1967) 431-450].
Keywords
Cite
@article{arxiv.0810.1638,
title = {On the existence of shortest directed networks},
author = {Konrad J Swanepoel},
journal= {arXiv preprint arXiv:0810.1638},
year = {2008}
}
Comments
6 pages. An old paper from 2000