arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.14945math.COcs.DM
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一个更好的密度增量定理及其对Hadwiger猜想的应用

An even better Density Increment Theorem and its application to Hadwiger's Conjecture

Luke Postle

摘要:

在1943年,Hadwiger证明了没有$K_t$子图的图对每个$t\ge 1$都是$(t-1)$ -可着色的。在20世纪80年代,Kostochka和Kristason独立证明了每个没有$K_t$子图的图都有平均度$O(t\sqrt{\log t})$,因此是$O(t\sqrt{\log t})$ -可着色的。最近,Norin,Song和作者证明了每个没有$K_t$子图的图对于每个$β> 1/4$都是$O(t(\log t)^β)$ -可着色的,这是对$O(t\sqrt{\log t})$界的数量级的第一次改进。最近,作者证明了每个没有$K_t$子图的图对于每个$β> 0$都是$O(t (\log t)^β)$可着色的;更具体地说,它们是$t \cdot 2^{ O((\log \log t)^{2/3}) }$可着色的。结合这一工作,本文证明了任何不含$K_t$子图的图都是$O(t (\log \log t)^{6})$ -可着色的。

英文摘要:

In 1943, Hadwiger conjectured that every graph with no $K_t$ minor is $(t-1)$-colorable for every $t\ge 1$. In the 1980s, Kostochka and Thomason independently proved that every graph with no $K_t$ minor has average degree $O(t\sqrt{\log t})$ and hence is $O(t\sqrt{\log t})$-colorable. Recently, Norin, Song and the author showed that every graph with no $K_t$ minor is $O(t(\log t)^β)$-colorable for every $β> 1/4$, making the first improvement on the order of magnitude of the $O(t\sqrt{\log t})$ bound. More recently, the author showed that every graph with no $K_t$ minor is $O(t (\log t)^β)$-colorable for every $β> 0$; more specifically, they are $t \cdot 2^{ O((\log \log t)^{2/3}) }$-colorable. In combination with that work, we show in this paper that every graph with no $K_t$ minor is $O(t (\log \log t)^{6})$-colorable.

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。

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