Steiner Minimal Trees

The problem of "Shortest Connectivity", which is discussed here, has a long and convoluted history. Many scientists from many fields as well as laymen have stepped on its stage. Usually, the problem is known as Steiner's Problem and it can be described more precisely in the following way: Given a finite set of points in a metric space, search for a network that connects these points with the shortest possible length. This shortest network must be a tree and is called a Steiner Minimal Tree (SMT). It may contain vertices different from the points which are to be connected. Such points are called Steiner points. Steiner's Problem seems disarmingly simple, but it is rich with possibilities and difficulties, even in the simplest case, the Euclidean plane. This is one of the reasons that an enormous volume of literature has been published, starting in 1 the seventeenth century and continuing until today. The difficulty is that we look for the shortest network overall. Minimum span ning networks have been well-studied and solved eompletely in the case where only the given points must be connected. The novelty of Steiner's Problem is that new points, the Steiner points, may be introduced so that an intercon necting network of all these points will be shorter. This also shows that it is impossible to solve the problem with combinatorial and geometric methods alone.

Klappentext

This book is the result of 18 years of research into Steiner's problem and its relatives in theory and application. Starting with investigations of shortest networks for VLSI layout and, on the other hand, for certain facility location problems, the author has found many common properties for Steiner's problem in various spaces. The purpose of the book is to sum up and generalize many of these results for arbitrary finite-dimensional Banach spaces. It shows that we can create a homogeneous and general theory when we consider two dimensions of such spaces, and that we can find many facts which are helpful in attacking Steiner's problem in the higher-dimensional cases. The author examines the underlying mathematical properties of this network design problem and demonstrates how it can be attacked by various methods of geometry, graph theory, calculus, optimization and theoretical computer science. br/ emAudience:/em All mathematicians and users of applied graph theory.

Zusammenfassung
The novelty of Steiner's Problem is that new points, the Steiner points, may be introduced so that an intercon necting network of all these points will be shorter.

Inhalt
1 Introduction.- 2 SMT and MST in Metric Spaces A Survey.- 3 Fermat's Problem in Banach-Minkowski Spaces.- 4 The Degrees of the Vertices in Shortest Trees.- 5 1-Steiner-Minimal-Trees.- 6 Methods to Construct Shortest Trees.- 7 The Steiner Ratio of Banach-Minkowski Spaces.- 8 Generalizations.- References.