Connected and/or topological group pd-examples
Abstract
The pinning down number of a topological space is the smallest cardinal such that for every neighborhood assignment on there is a set of size that meets every member of . Clearly, and we call a pd-example if . We denote by the class of all singular cardinals that are not strong limit. It was proved in a paper of Juh\'asz,Soukup and Szentmikl\'ossy (arXiv:1506.00206}) that TFAE: (1) ; (2) there is a 0-dimensional pd-example; (3) there is a pd-example. The aim of this paper is to produce pd-examples with further interesting topological properties like connectivity or being a topological group by presenting several constructions that transform given pd-examples into ones with these additional properties. We show that is also equivalent to the existence of a connected and locally connected pd-example, as well as to the existence of an abelian topological group pd-example. However, in itself is not sufficient to imply the existence of a connected pd-example. But if there is with then there is an abelian topological group (hence ) pd-example which is also arcwise connected and locally arcwise connected. Finally, the same assumption even implies that there is a locally convex topological vector space pd-example.
Keywords
Cite
@article{arxiv.1705.02622,
title = {Connected and/or topological group pd-examples},
author = {Istvan Juhász and Jan van Mill and Lajos Soukup and Zoltán Szentmiklóssy},
journal= {arXiv preprint arXiv:1705.02622},
year = {2017}
}
Comments
14 pages