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arXiv 2008.08797math.LO
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DP-极小投射有限群与整数赋值

Dp-minimal profinite groups and valuations on the integers

Tim Clausen

摘要:

研究了具有一致可定义的基本开子群系的dp-极小无限投射有限群。我们证明了这些群有一个开子群$A$,使得对于某个素数$p$,$A$是$\mathbb{F}_p$的可数多个拷贝的直积,或者$A$是$A \cong \prod_p \mathbb{Z}_p^{α_p} \times A_p$的形式,其中对于每个素数$p$,$α_p < ω$和$A_p$是有限阿贝尔$p$ -群.此外,我们证明,如果$A$是这种形式,那么有一个基本系统的开子群,使$A$由这个家庭的子群是dp-最小的。我们的主要内容是一类值交换群的量词消去结果。我们也将其应用到$(\mathbb{Z},+)$,我们表明,如果我们扩大$(\mathbb{Z},+)$由任何链的子群$(B_i)_{i<ω}$,我们得到一个dp-最小结构。这个结构是远端的,当且仅当子$B_i/B_{i+1}$的大小是有界的。

英文摘要:

We study dp-minimal infinite profinite groups that are equipped with a uniformly definable fundamental system of open subgroups. We show that these groups have an open subgroup $A$ such that either $A$ is a direct product of countably many copies of $\mathbb{F}_p$ for some prime $p$, or $A$ is of the form $A \cong \prod_p \mathbb{Z}_p^{α_p} \times A_p$ where $α_p < ω$ and $A_p$ is a finite abelian $p$-group for each prime $p$. Moreover, we show that if $A$ is of this form, then there is a fundamental system of open subgroups such that the expansion of $A$ by this family of subgroups is dp-minimal. Our main ingredient is a quantifier elimination result for a class of valued abelian groups. We also apply it to $(\mathbb{Z},+)$ and we show that if we expand $(\mathbb{Z},+)$ by any chain of subgroups $(B_i)_{i<ω}$, we obtain a dp-minimal structure. This structure is distal if and only if the size of the quotients $B_i/B_{i+1}$ is bounded.

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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