论文标题
$(m,n)$ - 彩色混合图的颜色
Colourings of $(m, n)$-coloured mixed graphs
论文作者
论文摘要
在非正式上,混合图是从简单的无向图获得的对象,通过为其边缘的子集选择一个方向。混合图为$(m,n)$ - 如果分配了每个边缘的$ M \ geq 0 $颜色之一,并且将每个弧分配为$ n \ geq 0 $颜色之一。面向的图形为$(0,1)$ - 彩色混合图,2边色的图为$(2,0)$ - 彩色混合图。我们表明,Sopena用于定向图的顶点着色的结果,以及Kostochka,Sopena和Zhu的顶点颜色图和2边色的图形的结果,是有关$(M,N)$彩色混合图的顶点颜色的特殊情况。这两个都可以视为布鲁克斯定理的一种版本。
A mixed graph is, informally, an object obtained from a simple undirected graph by choosing an orientation for a subset of its edges. A mixed graph is $(m, n)$-coloured if each edge is assigned one of $m \geq 0$ colours, and each arc is assigned one of $n \geq 0$ colours. Oriented graphs are $(0, 1)$-coloured mixed graphs, and 2-edge-coloured graphs are $(2, 0)$-coloured mixed graphs. We show that results of Sopena for vertex colourings of oriented graphs, and of Kostochka, Sopena and Zhu for vertex colourings oriented graphs and 2-edge-coloured graphs, are special cases of results about vertex colourings of $(m, n)$-coloured mixed graphs. Both of these can be regarded as a version of Brooks' Theorem.