On transforming a spatial graph into a plane graph
On transforming a spatial graph into a plane graph
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关于将空间图转化为平面图
DOI:
10.1143/ptps.191.225
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发表时间:
2011
影响因子:
--
通讯作者:
Akio Kawauchi
中科院分区:
文献类型:
--
作者:
F. Kaneda;S.-Y. Baek;M. Ozawa;K.Edamatsu;Nobuhiko Terui;二木昭人;H.Tokunaga;Akio Kawauchi
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 (γΓ)-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 (γΓ)-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.