List colourings of planar graphs
List colourings of planar graphs
复制标题
DOI:
10.1016/0012-365x(93)90579-i
复制
发表时间:
2006-05
期刊:
影响因子:
--
通讯作者:
M. Voigt
中科院分区:
文献类型:
--
作者:
M. Voigt
A graphG=G(V,E) is called L-list colourableif there is a vertex colouring ofGin which the colour assigned to a vertexvis chosen from a listL(v) associated with this vertex. We sayGisk-choosableif all listsL(v) have the cardinalitykandGis L-list colourable for all possible assignments of such lists. There are two classical conjectures from Erdős, Rubin and Taylor 1979 about the choosability of planar graphs:(1)every planar graph is 5-choosable and,(2)there are planar graphs which are not 4-choosable.We will prove the second conjecture.