论文标题

在局部抗原色数中的吊坠数量

On number of pendants in local antimagic chromatic number

论文作者

Lau, Gee-Choon, Shiu, Wai-Chee, Ng, Ho-Kuen

论文摘要

连接图的边缘标记$ g =(v,e)$,如果是二维$ f:e \ to \ to \ {1,\ ldots,| e | \} $,则是局部反象征,因此对于任何一对相邻的顶点$ x $ x $ and $ x $ and $ x $,$ f^+(x) \ sum f(e)$,$ e $在所有事件的边缘范围内到$ x $。 $ g $的本地抗原色数,用$χ_{la}(g)$表示,是所有本地抗原标签上$ g $的最小诱导顶点标签的最小数量。令$χ(g)$为$ g $的色数。在本文中,获得$ g $的$χ_{la}(g)$的尖锐上限和下限,并获得了足够的条件,并获得了足够的条件使得相等。因此,对于$ k \ ge 1 $,有许多图形,带有$ k \geχ(g)-1 $吊坠顶点,$χ_{la}(g)= k+1 $。我们推测,除某些毛毛虫,蜘蛛和龙虾外,每棵树$ t_k $都有$ k \ ge 1 $ pendant顶点具有$χ_{la}(t_k)= k+1 $。

An edge labeling of a connected graph $G = (V, E)$ is said to be local antimagic if it is a bijection $f:E \to\{1,\ldots ,|E|\}$ such that for any pair of adjacent vertices $x$ and $y$, $f^+(x)\not= f^+(y)$, where the induced vertex label $f^+(x)= \sum f(e)$, with $e$ ranging over all the edges incident to $x$. The local antimagic chromatic number of $G$, denoted by $χ_{la}(G)$, is the minimum number of distinct induced vertex labels over all local antimagic labelings of $G$. Let $χ(G)$ be the chromatic number of $G$. In this paper, sharp upper and lower bounds of $χ_{la}(G)$ for $G$ with pendant vertices, and sufficient conditions for the bounds to equal, are obtained. Consequently, for $k\ge 1$, there are infinitely many graphs with $k \ge χ(G) - 1$ pendant vertices and $χ_{la}(G) = k+1$. We conjecture that every tree $T_k$, other than certain caterpillars, spiders and lobsters, with $k\ge 1$ pendant vertices has $χ_{la}(T_k) = k+1$.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源