围长至少是4的特殊平面图的3-可选择性

The 3-choosability of special plane graphs with girth of 4 at least

图G的选择数定义为最小的自然数k,满足对任一顶点给定k种颜色的列表,且染色时每个顶点的颜色只能从自身的颜色列表中选择,总存在图G顶点的一个正常着色.通过权转移的方法证明了每个围长至少是4且不含6-圈,9-圈和11-圈的平面图是3-可选择的.

The choice number of a graph Gis defined as a minimum number ksuch that if a list of kcolors is given to an arbitrary vertex of G,there will be a vertex coloring in G,where each vertex will choose a color only from its own list of colors,and a normal coloring at a vertex of Ggraph will necessarily exist always.It is verified by means of weight shifting method that every plane graph with girth of 4at least and without 6-,9-and 11-cycles will be 3-choosable.