Swanepoel, Konrad 
ORCID: 0000-0002-1668-887X 
  
(2000)
The local Steiner problem in normed planes.
    Networks, 36 (2).
     pp. 104-113.
     ISSN 0028-3045
  
  
  
Abstract
We present a geometric analysis of the local structure of vertices in a Steiner minimum tree in an arbitrary normed plane in terms of so-called absorbing and critical angles, thereby unifying various results known for specific norms. We find necessary and sufficient conditions for a set of segments emanating from a point to be the neighborhood of a vertex in a Steiner minimum tree. As corollaries, we show that the maximum possible degree of a Steiner point and of a given point are equal, and equal 3 or 4, except if the unit ball is an affine regular hexagon, where it is known that the maximum degree of a Steiner point is 4 and of a regular point is 6. We also characterize the planes where the maximum degree is 4, the so-called X-planes, and present examples. In particular, if the unit ball is an affine regular 2n-gon, Steiner points of degree 4 exist if and only if n = 2, 3, 4, or 6.
| Item Type: | Article | 
|---|---|
| Official URL: | http://www3.interscience.wiley.com/journal/32046/ | 
| Additional Information: | © 2000 Wiley Periodicals | 
| Divisions: | Mathematics | 
| Subjects: | Q Science > QA Mathematics | 
| Date Deposited: | 16 Oct 2009 09:35 | 
| Last Modified: | 11 Sep 2025 06:16 | 
| URI: | http://eprints.lse.ac.uk/id/eprint/25466 | 
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