论文标题
$ g $ free图的极端结果
Extremal results on $G$-free colorings of graphs
论文作者
论文摘要
令$ h =(v(h),e(h))$为图。 $ k $ - 颜色的$ h $是映射$π:v(h)\ longrightArrow \ {1,2,\ ldots,k \} $,以便每个颜色类都诱导$ k_2 $ free-free子图。对于图$ g $的订单,至少$ 2 $,$ g $ -free $ k $ - 颜色为$ h $的映射$π:v(h)\ longrightArrow \ {1,2,\ ldots,k \} $,以便由$ h $的$ h $的子类别由每种颜色的$ h $类别$ f $ g $ g $ g $ f $ fefe. $ g $ free $ h $的$ h $是最低数字$ k $,因此有$ g $ - free $ k $ - 颜色为$ h $,用$χ_g(h)$表示。图形$ h $是唯一的$ k $ - $ g $ - 如果$χ_g(h)= k $和每个$ k $ - $ g $ -free $ h $的$ h $的颜色都会产生相同的颜色类别。对于$ g $ - free或$ g $ -free-Minimal,图形$ h $是最小的,如果对于$ e(h)$的每个边缘,我们都有$χ_g(h \ setMinus \ {e \})=χ_g(h)-1 $。在本文中,我们提供了一些界限和属性,涉及$ k $ - $ g $ - 免费着色和$ k $ - $ g $ -free-rinimal。
Let $H=(V(H),E(H))$ be a graph. A $k$-coloring of $H$ is a mapping $π: V(H) \longrightarrow \{1,2,\ldots, k\}$ so that each color class induces a $K_2$-free subgraph. For a graph $G$ of order at least $2$, a $G$-free $k$-coloring of $H$ is a mapping $π: V(H) \longrightarrow \{1,2,\ldots,k\}$ so that the subgraph of $H$ induced by each color class of $π$ is $G$-free, i.e. contains no copy of $G$. The $G$-free chromatic number of $H$ is the minimum number $k$ so that there is a $G$-free $k$-coloring of $H$, denoted by $χ_G(H)$. A graph $H$ is uniquely $k$-$G$-free colouring if $χ_G(H)=k$ and every $k$-$G$-free colouring of $H$ produces the same color classes. A graph $H$ is minimal with respect to $G$-free, or $G$-free-minimal, if for every edges of $E(H)$ we have $χ_G(H\setminus\{e\})= χ_G(H)-1$. In this paper we give some bounds and attribute about uniquely $k$-$G$-free colouring and $k$-$G$-free-minimal.