关于无限多种颜色或有限单色集合的 Owings 型定理
Owings-like theorems for infinitely many colours or finite monochromatic sets
AI总结:
本文推广Owings问题,研究阿贝尔群着色下单色和集的存在性,完全解决了基数κ与θ同为有限或同为无限的情况,并部分解决了θ无限κ有限的情况。
摘要:
受 Owings 问题启发,我们研究对于给定的阿贝尔群 $G$ 和基数 $κ,θ$,是否每种着色 $c:G\longrightarrowθ$ 都会产生一个子集 $X\subseteq G$,满足 $|X|=κ$ 且 $X+X$ 是单色的。(Owings 问题针对 $G=\mathbb Z$、$θ=2$ 和 $κ=\aleph_0$ 提出此问;已知对于相同的 $G$ 和 $κ$ 但 $θ=3$ 时结论为否。)我们完全解决了 $κ$ 和 $θ$ 均为有限的情况(通过获得肯定回答的充分必要条件),以及 $κ$ 和 $θ$ 均为无限的情况(结论为否定)。此外,在 $θ$ 为无限而 $κ$ 为有限的情况下,我们得到了否定回答的一些充分条件以及一个肯定回答的实例。
英文摘要:
Inspired by Owings's problem, we investigate whether, for a given an Abelian group $G$ and cardinal numbers $κ,θ$, every colouring $c:G\longrightarrowθ$ yields a subset $X\subseteq G$ with $|X|=κ$ such that $X+X$ is monochromatic. (Owings's problem asks this for $G=\mathbb Z$, $θ=2$ and $κ=\aleph_0$; this is known to be false for the same $G$ and $κ$ but $θ=3$.) We completely settle the question for $κ$ and $θ$ both finite (by obtaining sufficient and necessary conditions for a positive answer) and for $κ$ and $θ$ both infinite (with a negative answer). Also, in the case where $θ$ is infinite but $κ$ is finite, we obtain some sufficient conditions for a negative answer as well as an example with a positive answer.
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。