European Journal of Combinatorics ( IF 1.0 ) Pub Date : 2021-03-10 , DOI: 10.1016/j.ejc.2021.103327 Ligang Jin , Yingli Kang
In a proper edge-coloring of a cubic graph, an edge is normal if the set of colors used by the five edges incident with an end of has cardinality 3 or 5. The Petersen coloring conjecture asserts that every bridgeless cubic graph has a normal 5-edge-coloring, that is, a proper 5-edge-coloring such that all edges are normal. In this paper, we prove a result related to the Petersen coloring conjecture. The parameter is a measurement for cubic graphs, introduced by Steffen in 2015. Our result shows that every bridgeless cubic graph has a proper 5-edge-coloring such that at least (which is no less than ) edges are normal. This result improves on some earlier results of Bílková and Šámal.
中文翻译:
三次图的部分正态5边色
在对立方图进行适当的边着色时,边 如果五个边沿所入射的一组颜色所使用的一组颜色是正常的,则这是正常的 具有3或5的基数。Petersen着色猜想断言,每个无桥三次方图都有正常的5边缘着色,即,适当的5边缘着色使得所有边缘都是正常的。在本文中,我们证明了与彼得森着色猜想有关的结果。参数 是由Steffen在2015年推出的对立方图的度量。我们的结果表明,每个无桥立方图 具有适当的5边色,使得至少 (不少于 )边缘是正常的。此结果比Bílková和Šámal的一些早期结果有所改进。