First countable spaces without point-countable $\pi$-base
General Topology
2007-05-23 v1
Abstract
We answer several questions of V. Tka\v{c}uk from [Point-countable -bases in first countable and similar spaces, Fund. Math. 186 (2005), pp. 55--69.] by showing that (1) there is a ZFC example of a first countable, 0-dimensional Hausdorff space with no point-countable -base (in fact, the order of any -base of the space is at least ); (2) if there is a -Suslin line then there is a first countable GO space of cardinality in which the order of any -base is at least ; (3) it is consistent to have a first countable, hereditarily Lindel\" of regular space having uncountable -weight and as a caliber (of course, such a space cannot have a point-countable -base).
Keywords
Cite
@article{arxiv.math/0703728,
title = {First countable spaces without point-countable $\pi$-base},
author = {Istvan Juhasz and Lajos Soukup and Zoltan Szentmiklossy},
journal= {arXiv preprint arXiv:math/0703728},
year = {2007}
}