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arXiv 1809.09347math.CO
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关于最大度为4的可平面图的3-可选性的注记

Note on 3-Choosability of Planar Graphs with Maximum Degree 4

François Dross, Borut Lužar, Mária Maceková, Roman Soták

摘要:

判定一个可平面图(即使是最大度的图$4$)是否是$3$ -可着色的是NP-完全的。确定平面图的子类是$3$ -可着色的有很长的历史,但自从Grötzsch的结果,三角形自由可平面图是这样的,大部分的努力集中在解决哈维尔和斯坦伯格的图。本文证明了作为任意二部平面图的中间图的子图得到的最大度平面图$4$是$3$ -可选的.这些图允许有闭合的三角形(甚至是关联的),并且没有禁止的短圈,因此代表了与上述图推断的完全不同的一类图。

英文摘要:

Deciding whether a planar graph (even of maximum degree $4$) is $3$-colorable is NP-complete. Determining subclasses of planar graphs being $3$-colorable has a long history, but since Grötzsch's result that triangle-free planar graphs are such, most of the effort was focused to solving Havel's and Steinberg's conjectures. In this paper, we prove that every planar graph of maximum degree $4$ obtained as a subgraph of the medial graph of any bipartite plane graph is $3$-choosable. These graphs are allowed to have close triangles (even incident), and have no short cycles forbidden, hence representing an entirely different class than the graphs inferred by the above mentioned conjectures.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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