Topology and its Applications ( IF 0.6 ) Pub Date : 2021-07-21 , DOI: 10.1016/j.topol.2021.107797 Taras Banakh 1, 2 , Mikhail Tkachenko 3
Given a paratopological group G and a class of continuous homomorphisms of paratopological groups, we define the -semicompletion and -completion of the group G that contain G as a dense subgroup, satisfy the -separation axiom and have certain universality properties. For special classes , we present some necessary and sufficient conditions on G in order that the (semi)completions and be Hausdorff. Also, we give an example of a Hausdorff paratopological abelian group G whose -semicompletion fails to be a -space, where is the class of continuous homomorphisms of sequentially compact topological groups to paratopological groups. In particular, the group G contains an ω-bounded sequentially compact subgroup H such that H is a topological group but its closure in G fails to be a subgroup.
中文翻译:
副拓扑群的弱补全
给定一个 超拓扑群G和一个类 的互补拓扑群的连续同态,我们定义 -半完成 和 -完成 该组的ģ包含ģ作为致密子群,满足-分离公理并具有一定的普适性。对于特殊班,我们提出G上的一些充要条件,以便(半)完成 和 成为豪斯多夫。此外,我们还给出了一个 Hausdorff 副拓扑阿贝尔群G的例子,它的-半完成 不是一个 -空间,哪里 是顺序紧拓扑群到副拓扑群的连续同态类。特别地,群G包含一个ω 有界的顺序紧致子群H,使得H是一个拓扑群,但它在G 中的闭包不能是一个子群。