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On point-halfspace graphs

✍ Scribed by Edward R. Scheinerman; Ann N. Trenk; Daniel Ullman


Book ID
102893239
Publisher
John Wiley and Sons
Year
1995
Tongue
English
Weight
744 KB
Volume
20
Category
Article
ISSN
0364-9024

No coin nor oath required. For personal study only.

✦ Synopsis


Abstract

The following definition is motivated by the study of circle orders and their connections to graphs. A graphs G is called a point‐halfspace graph (in R^k^) provided one can assign to each vertex v ϵ (G) a point p~v~ R^k^ and to each edge e ϵ E(G) a closed halfspace H~e~ ϵ R^k^ so that v is incident with e if and only if p~v~ ϵ H~e~. Let H^k^ denote the set of point‐halfspace graphs (in R^k^).

We give complete forbidden subgraph and structural characterizations of the classes H^k^ for every k. Surprisingly, these classes are closed under taking minors and we give forbidden minor characterizations as well. © 1996 John Wiley & Sons, Inc.


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