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arXiv 2108.03549math.CO
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伪多扇与棒棒糖

Pseudo-multifan and Lollipop

Yan Cao, Guantao Chen, Guangming Jing, Songling Shan

AI总结:

本文发展了边着色图中的“伪多扇”与“棒棒糖”概念,并证明它们是研究小核度图边着色问题的有力工具,为解决Hilton和Zhao的核猜想提供了新方法。

摘要:

最大度为$Δ$的简单图$G$若满足$|E(G)|>Δ\lfloor |V(G)|/2\rfloor$,则称其为过满的。$G$的核,记为$G_Δ$,是由$G$中度为$Δ$的顶点导出的子图。显然,若$G$过满,则$G$的边色数为$Δ+1$。反之,Hilton和Zhao于1996年猜想:若$G$是$Δ\ge 3$且$Δ(G_Δ)\le 2$的简单连通图,则$χ'(G)=Δ+1$意味着$G$过满或$G=P^*$,其中$P^*$由Petersen图删除一个顶点得到(核猜想)。本文旨在发展“伪多扇”与“棒棒糖”的概念,并研究它们在边着色图中的性质。这些概念被证明是研究具有小核度的图的边着色问题的有力工具。

英文摘要:

A simple graph $G$ with maximum degree $Δ$ is \emph{overfull} if $|E(G)|>Δ\lfloor |V(G)|/2\rfloor$. The \emph{core} of $G$, denoted $G_Δ$, is the subgraph of $G$ induced by its vertices of degree $Δ$. Clearly, the chromatic index of $G$ equals $Δ+1$ if $G$ is overfull. Conversely, Hilton and Zhao in 1996 conjectured that if $G$ is a simple connected graph with $Δ\ge 3$ and $Δ(G_Δ)\le 2$, then $χ'(G)=Δ+1$ implies that $G$ is overfull or $G=P^*$, where $P^*$ is obtained from the Petersen graph by deleting a vertex (Core Conjecture). The goal of this paper is to develop the concepts of ``pseudo-multifan'' and ``lollipop'' and study their properties in an edge colored graph. These concepts turn out to be powerful tools in edge coloring graphs with a small core degree.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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