Concentrated sets and the Hurewicz property
General Topology
2025-11-13 v1
Abstract
A set of reals is -concentrated if it has cardinality at least and it contains a countable set such that each closed subset of disjoint with has size smaller than . We present ZFC results about structures of -concentrated sets with the Hurewicz covering property using semifilters. Then we show that assuming that the semifilter trichotomy holds, then each -concentrated set is Hurewicz and even productively Hurewicz. We also show that the appearance of Hurewicz -concentrated sets under the semifilter trichotomy is somewhat specific and the situation in the Laver model for the consitency of the Borel Conjecture is different.
Cite
@article{arxiv.2511.09320,
title = {Concentrated sets and the Hurewicz property},
author = {Valentin Haberl and Piotr Szewczak and Lyubomyr Zdomskyy},
journal= {arXiv preprint arXiv:2511.09320},
year = {2025}
}
Comments
20 p