arXiv 2104.007162021-04-01math.CO

超立方体部分边着色的避免和推广

Avoiding and extending partial edge colorings of hypercubes

Carl Johan Casselgren, Per Johansson, Klas Markström

摘要：

考虑超立方体的部分边着色的推广和避免问题，即给定$d$维超立方体$Q_d$的部分边着色$φ$，我们关心的是是否存在$Q_d$的正确$d$ -边着色，它与在$φ$下着色的每条边的着色$φ$一致;或者，类似地，如果在$φ$下着色的每个边上存在与$φ$不一致的适当的$d$ -边着色。特别地，我们证明了对任何$d\geq 1$，如果$φ$是$Q_d$的部分$d$ -边染色，则$φ$是可避免的，如果每种颜色都出现在至多$d/8$边上，并且该染色满足一个相对温和的结构条件，或者$φ$是适当的，并且每种颜色都出现在至多$d-2$边上.我们还证明了如果$d$可被$3$整除且$φ$的每一个颜色类都是诱导匹配，则同样的结论也成立。此外，对于所有的$1 \leq k \leq d$，我们的特征在于，其中配置组成的部分着色$φ$的$d-k$边缘和部分着色$ψ$的$k$边缘，有一个扩展的$φ$，避免了$ψ$。

英文摘要：

We consider the problem of extending and avoiding partial edge colorings of hypercubes; that is, given a partial edge coloring $φ$ of the $d$-dimensional hypercube $Q_d$, we are interested in whether there is a proper $d$-edge coloring of $Q_d$ that agrees with the coloring $φ$ on every edge that is colored under $φ$; or, similarly, if there is a proper $d$-edge coloring that disagrees with $φ$ on every edge that is colored under $φ$. In particular, we prove that for any $d\geq 1$, if $φ$ is a partial $d$-edge coloring of $Q_d$, then $φ$ is avoidable if every color appears on at most $d/8$ edges and the coloring satisfies a relatively mild structural condition, or $φ$ is proper and every color appears on at most $d-2$ edges. We also show that the same conclusion holds if $d$ is divisible by $3$ and every color class of $φ$ is an induced matching. Moreover, for all $1 \leq k \leq d$, we characterize for which configurations consisting of a partial coloring $φ$ of $d-k$ edges and a partial coloring $ψ$ of $k$ edges, there is an extension of $φ$ that avoids $ψ$.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

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