论文标题
1平面图的强色指数
The strong chromatic index of 1-planar graphs
论文作者
论文摘要
图$ g $的色度索引$χ'(g)$是$ g $的最小$ k $,$ g $承认边缘$ k $ - 颜色,以使任何两个相邻的边缘具有不同的颜色。 $ g $的强色索引$χ'_s(g)$是最小的$ k $,因此$ g $具有边缘$ k $ - 颜色的,条件是距离最多两个边的任何两个边都会获得不同的颜色。如果可以在平面中绘制图形,则图为1平面,使每个边缘在最多另一个边缘越过。在本文中,我们表明每个图$ g $具有最高平均度$ \ bar {d}(g)$具有$χ'__ {s}(g)(g)\ le(2 \ bar {d}(g)-1 -1)χ'(g)$。作为推论,我们证明,每1平面图$ g $具有最高度$δ$具有$χ'_{\ rm s}(g)\ le14δ$,这会改善结果,这是由于Bensmail等人的,这说明$χ'__ _ _ _ _ {\ rm s}(g)(g)(g)\ le24δ$
The chromatic index $χ'(G)$ of a graph $G$ is the smallest $k$ for which $G$ admits an edge $k$-coloring such that any two adjacent edges have distinct colors. The strong chromatic index $χ'_s(G)$ of $G$ is the smallest $k$ such that $G$ has an edge $k$-coloring with the condition that any two edges at distance at most 2 receive distinct colors. A graph is 1-planar if it can be drawn in the plane so that each edge is crossed by at most one other edge. In this paper, we show that every graph $G$ with maximum average degree $\bar{d}(G)$ has $χ'_{s}(G)\le (2\bar{d}(G)-1)χ'(G)$. As a corollary, we prove that every 1-planar graph $G$ with maximum degree $Δ$ has $χ'_{\rm s}(G)\le 14Δ$, which improves a result, due to Bensmail et al., which says that $χ'_{\rm s}(G)\le 24Δ$ if $Δ\ge 56$.