Topological spaces with an $\omega^\omega$-base
Abstract
Given a partially ordered set we study properties of topological spaces admitting a -base, i.e., an indexed family of subsets of such that for all in and for every the family of balls is a neighborhood base at . A -base for is called locally uniform if the family of entourages remains a -base for . A topological space is first-countable if and only if it has an -base. By Moore's Metrization Theorem, a topological space is metrizable if and only if it is a -space with a locally uniform -base. In the paper we shall study topological spaces possessing a (locally uniform) -base. Our results show that spaces with an -base share some common properties with first countable spaces, in particular, many known upper bounds on the cardinality of first-countable spaces remain true for countably tight -based topological spaces. On the other hand, topological spaces with a locally uniform -base have many properties, typical for generalized metric spaces. Also we study Tychonoff spaces whose universal (pre- or quasi-) uniformity has an -base and show that such spaces are close to being -compact.
Cite
@article{arxiv.1607.07978,
title = {Topological spaces with an $\omega^\omega$-base},
author = {Taras Banakh},
journal= {arXiv preprint arXiv:1607.07978},
year = {2021}
}
Comments
105 pages