arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.01626math.GR
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不变生成和Houghton群

Invariable generation and the Houghton groups

Charles Garnet Cox

摘要:

Houghton群$H_1, H_2, \ldots$是无限群的一族。1975年,Wiegold证明了$H_3$总是生成(IG),但$H_1\le H_3$不是。一个自然的问题是,组$H_2, H_3, \ldots$是否都是IG。维戈尔德还结束说,在例子中,他发现了一个IG组的一个小组,是不是IG,小组从来没有有限的指数。另一个自然的问题是,在$H_3$中是否有一个非IG的有限指数子群。本文证明了对每个$n\in \{2, 3, \ldots\}$,$H_n$及其所有有限指数子群都是IG. Minasyan和Goffer-Lazarovich在2020年6月的独立工作很好地阐述了这一点:他们证明了IG群可以有一个有限的指数子群,而这个子群不是IG。

英文摘要:

The Houghton groups $H_1, H_2, \ldots$ are a family of infinite groups. In 1975 Wiegold showed that $H_3$ was invariably generated (IG) but $H_1\le H_3$ was not. A natural question is then whether the groups $H_2, H_3, \ldots$ are all IG. Wiegold also ends by saying that, in the examples he had found of an IG group with a subgroup that is not IG, the subgroup was never of finite index. Another natural question is then whether there is a subgroup of finite index in $H_3$ that is not IG. In this note we prove, for each $n\in \{2, 3, \ldots\}$, that $H_n$ and all of its finite index subgroups are IG. The independent work of Minasyan and Goffer-Lazarovich in June 2020 frames this note quite nicely: they showed that an IG group can have a finite index subgroup that is not IG.

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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