The 4-Choosability of Plane Graphs without 4-Cycles
نویسندگان
چکیده
منابع مشابه
The 4-choosability of planar graphs without 6-cycles
Let G be a planar graph without 6-cycles. We prove that G is 4-choosable.
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A graph is k-choosable if it can be colored whenever every vertex has a list of at least k available colors. We prove that if cycles of length at most four in a planar graph G are pairwise far apart, then G is 3-choosable. This is analogous to the problem of Havel regarding 3-colorability of planar graphs with triangles far apart.
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Let G be a toroidal graph without cycles of a fixed length k, and l (G) the list chromatic number of G. We establish tight upper bounds Contract grant sponsor: RGC; Contract grant number: CUHK4165/01E (to L. C.); Contract grant sponsor: NSFC; Contract grant number: 10771197 (to W. W.); Contract grant sponsor: ZJNSFC; Contract grant number: Z6090150 (to W. W.); Contract grant sponsor: NSC97-2115...
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ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series B
سال: 1999
ISSN: 0095-8956
DOI: 10.1006/jctb.1998.1893