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Prog. Theor. Phys. Supplement No.191 (2011) pp. 225-234

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On Transforming a Spatial Graph into a Plane Graph

Akio Kawauchi*

Department of Mathematics, Osaka City University, Osaka 558-8585, Japan

(Received September 15, 2010)

Abstract:

This article is a revised detailed version of the research announcement [Bussei Kenkyu 92 (2009), 16] introducing a complexity of a spatial graph, which is useful to transform a spatial graph (without degree one vertices) into a plane graph. We also introduce related topological invariants for every spatial graph, called the warping degree, and γ- warping degree and (γ,Γ)- warping degree. We also generalize the usual unknotting number of a knot to every spatial graph and introduce related topological invariants for every spatial graph, called the γ- unknotting number, Γ- unknotting number and (γ,Γ)- unknotting number. These invariants are used to define “semi-topological” invariants for a spatial graph with degree one vertices, meaningful even for a knotted arc.


URL : http://ptp.ipap.jp/link?PTPS/191/225/
DOI : 10.1143/PTPS.191.225


*E-mail: kawauchi@sci.osaka-cu.ac.jp

[ Full Text PDF : FREE ACCESS (449K) ] Citation:


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