论文标题

关于与平面图的分离及其对应着色类似物的可选性

On the choosability with separation of planar graphs and its correspondence colouring analogue

论文作者

Smith-Roberge, Evelyne

论文摘要

图$ g $的列表分配$ l $是$(\ ell,k)$ - 列表分配,如果$ | l(v)| \ geq \ ell $ for v(g)$ in v(g)$和$ | l(u)\ cap l(v)| \ e(g)$中的每个$ uv \ for \ leq k $。我们说$ g $是$(\ ell,k)$ - 如果承认每$(\ ell,k)$的$ l $颜色,则可以选择。我们证明,如果$ g $是带有$(4,2)$ - 列表分配$ l $的平面图,对于每个三角形$ t \ subseteq g $,我们都有$ | \ bigcap_ {v \ in V(t)} l(v)| \ neq 2 $,然后$ g $是$ l $ - 颜色。实际上,我们证明结果稍强:如果$ g $包含一个集团$ h $,则每个三角形$ v(h)\ cap v(t)\ neq \ embtySet $ for for for每个三角形$ t \ subseteq g $带有$ | \ bigCap_ = 2 $,然后$ g $是$ l $ - 颜色。此外,我们对$(4,2)$ - 平面图的可调性的对应着色类似物进行了反例。

A list assignment $L$ for a graph $G$ is an $(\ell,k)$-list assignment if $|L(v)|\geq \ell$ for each $v \in V(G)$ and $|L(u) \cap L(v)| \leq k$ for each $uv \in E(G)$. We say $G$ is $(\ell,k)$-choosable if it admits an $L$-colouring for every $(\ell, k)$-list assignment $L$. We prove that if $G$ is a planar graph with $(4,2)$-list assignment $L$ and for every triangle $T \subseteq G$ we have that $|\bigcap_{v \in V(T)} L(v)| \neq 2$, then $G$ is $L$-colourable. In fact, we prove a slightly stronger result: if $G$ contains a clique $H$ such that $V(H) \cap V(T) \neq \emptyset$ for every triangle $T \subseteq G$ with $|\bigcap_{v \in V(T)} L(v)| = 2$, then $G$ is $L$-colourable. Additionally, we give a counterexample to the correspondence colouring analogue of $(4,2)$-choosability for planar graphs.

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