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arXiv 2205.05751math.LOmath.CO
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可测的domatic划分

Measurable domatic partitions

Edward Hou

AI总结:

本文研究了紧致Polish群上Schreier图的domatic划分,证明了连续与Baire可测划分的存在性等价于子集拓扑闭包不可数,且Haar可测划分总存在,并推广至描述性图组合背景。

摘要:

设$Γ$为有限拓扑维数的紧致Polish群。对于可数无穷子集$S\subseteq Γ$,domatic $\aleph_0$-划分(针对其在$Γ$上的Schreier图)是一个偏函数$f:Γ\rightharpoonup\mathbb{N}$,使得对每个$x\in Γ$,有$f[S\cdot x]=\mathbb{N}$。我们证明,存在连续的domatic $\aleph_0$-划分当且仅当存在Baire可测的domatic $\aleph_0$-划分,当且仅当$S$的拓扑闭包不可数。对所有$S$的选择,均存在Haar可测的domatic $\aleph_0$-划分。我们还研究了在一般描述性图组合背景下的domatic划分。

英文摘要:

Let $Γ$ be a compact Polish group of finite topological dimension. For a countably infinite subset $S\subseteq Γ$, a domatic $\aleph_0$-partition (for its Schreier graph on $Γ$) is a partial function $f:Γ\rightharpoonup\mathbb{N}$ such that for every $x\in Γ$, one has $f[S\cdot x]=\mathbb{N}$. We show that a continuous domatic $\aleph_0$-partition exists, if and only if a Baire measurable domatic $\aleph_0$-partition exists, if and only if the topological closure of $S$ is uncountable. A Haar measurable domatic $\aleph_0$-partition exists for all choices of $S$. We also investigate domatic partitions in the general descriptive graph combinatorial setting.

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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