Tychonoff Expansions with Prescribed Resolvability Properties
Abstract
The recent literature offers examples, specific and hand-crafted, of Tychonoff spaces (in ZFC) which respond negatively to these questions, due respectively to Ceder and Pearson (1967) and to Comfort and Garc\'ia-Ferreira (2001): (1) Is every -resolvable space maximally resolvable? (2) Is every maximally resolvable space extraresolvable? Now using the method of expansion, the authors show that {\it every} suitably restricted Tychonoff topological space admits a larger Tychonoff topology (that is, an "expansion") witnessing such failure. Specifically the authors show in ZFC that if is a maximally resolvable Tychonoff space with , then has Tychonoff expansions (), with and , such that is: () -resolvable but not maximally resolvable; () [if is regular, with ] -resolvable for all , but not -resolvable; () maximally resolvable, but not extraresolvable; () extraresolvable, but not maximally resolvable; () maximally resolvable and extraresolvable, but not strongly extraresolvable.
Keywords
Cite
@article{arxiv.0910.0439,
title = {Tychonoff Expansions with Prescribed Resolvability Properties},
author = {W. W. Comfort and Wanjun Hu},
journal= {arXiv preprint arXiv:0910.0439},
year = {2023}
}
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25 pages, 0 figures