论文标题

适当的无冲突列表颜色,奇数未成年人,细分和分层的树宽

Proper conflict-free list-coloring, odd minors, subdivisions, and layered treewidth

论文作者

Liu, Chun-Hung

论文摘要

适当的无冲突着色是图形的适当着色和其正方形的适当着色之间的一个中间概念。它是一种合适的着色,因此对于每个非分离顶点,都有一种颜色,它在其(开放)邻域中出现一次。具有较大适当冲突的色数的图形的典型示例包括具有较大色度数的图形和双分形图的同构图,以$ 1 $ - 缩写为$ 1 $ - 具有较大色数的图形。在本文中,我们证明了两个粗糙的匡威语句,即使在列表颜色的设置中也可以。第一个是用于稀疏图:对于每个图$ h $,都存在一个整数$ c_h $,因此每个图形没有$ h $的每个图形都是(正确)无冲突$ C_H $ -CHOOSABLE。第二个适用于密集的图:每个具有较大冲突选择编号的图形都包含一个大图作为奇数小调,或者包含一个具有较大无冲突选择编号的二分诱导子图。这些给出了两个无与伦比的(部分)答案,这是Caro,Petruševski和škrekovski的问题。我们还证明,对于次要封闭的家庭而言,我们还具有更高的界限,这意味着文献中有关适当的无冲突着色和奇特着色的一些已知结果。此外,我们证明,所有带有分层树宽的图最多$ w $都是(正确的)无冲突$(8W-1)$ - 可chosable。此结果适用于$(g,k)$ - 平面图,它们的着色问题最近引起了注意。

Proper conflict-free coloring is an intermediate notion between proper coloring of a graph and proper coloring of its square. It is a proper coloring such that for every non-isolated vertex, there exists a color appearing exactly once in its (open) neighborhood. Typical examples of graphs with large proper conflict-free chromatic number include graphs with large chromatic number and bipartite graphs isomorphic to the $1$-subdivision of graphs with large chromatic number. In this paper, we prove two rough converse statements that hold even in the list-coloring setting. The first is for sparse graphs: for every graph $H$, there exists an integer $c_H$ such that every graph with no subdivision of $H$ is (properly) conflict-free $c_H$-choosable. The second applies to dense graphs: every graph with large conflict-free choice number either contains a large complete graph as an odd minor or contains a bipartite induced subgraph that has large conflict-free choice number. These give two incomparable (partial) answers of a question of Caro, Petruševski and Škrekovski. We also prove quantitatively better bounds for minor-closed families, implying some known results about proper conflict-free coloring and odd coloring in the literature. Moreover, we prove that every graph with layered treewidth at most $w$ is (properly) conflict-free $(8w-1)$-choosable. This result applies to $(g,k)$-planar graphs, which are graphs whose coloring problems have attracted attention recently.

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