arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1210.7895math.GRmath.GN
收藏

关于可拓扑群与不可拓扑群

On topologizable and non-topologizable groups

A. A. Klyachko, A. Yu. Olshanskii, D. V. Osin

摘要:

一个群$G$称为遗传不可拓扑的,如果对每个$H\le G$,没有$H$的商允许一个非离散Hausdorff拓扑。我们构造了第一个无限遗传不可拓扑群的例子。这使我们能够证明c-紧性并不意味着拓扑群的紧性。我们还回答了其他几个开放的问题,关于C-紧群问Dikranjan和Uspenskij。另一方面,我们提出了一种在标记$k$生成群空间中基于类属性质构造可拓扑群的方法。作为应用,我们证明了存在有限指数的非离散拟循环群,这回答了Morris和Obraztsov的一个问题。

英文摘要:

A group $G$ is called hereditarily non-topologizable if, for every $H\le G$, no quotient of $H$ admits a non-discrete Hausdorff topology. We construct first examples of infinite hereditarily non-topologizable groups. This allows us to prove that c-compactness does not imply compactness for topological groups. We also answer several other open questions about c-compact groups asked by Dikranjan and Uspenskij. On the other hand, we suggest a method of constructing topologizable groups based on generic properties in the space of marked $k$-generated groups. As an application, we show that there exist non-discrete quasi-cyclic groups of finite exponent; this answers a question of Morris and Obraztsov.

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。

↑