Dominating and pinning down pairs for topological spaces
Abstract
We call a pair of infinite cardinals with a dominating (resp. pinning down) pair for a topological space if for every subset of (resp. family of non-empty open sets in ) of cardinality there is of cardinality such that (resp. for each ). Clearly, a dominating pair is also a pinning down pair for . Our definitions generalize the concepts introduced in [GTW] resp. [BT] which focused on pairs of the form . The main aim of this paper is to answer a large number of the numerous problems from [GTW] and [BT] that asked if certain conditions on a space together with the assumption that or is a pinning down pair or \dominating pair for would imply . [BT] A. Bella, V.V. Tkachuk, Exponential density vs exponential domination, preprint [GTW] G. Gruenhage, V.V. Tkachuk, R.G. Wilson, Domination by small sets versus density, Topology and its Applications 282 (2020)
Keywords
Cite
@article{arxiv.2011.10261,
title = {Dominating and pinning down pairs for topological spaces},
author = {István Juhász and Lajos Soukup and Zoltán Szentmiklóssy},
journal= {arXiv preprint arXiv:2011.10261},
year = {2020}
}
Comments
16 pages