English

On the resolvability of Lindel\"of-generated and (countable extent)-generated spaces

General Topology 2018-04-10 v1

Abstract

Given a topological property PP, we say that the space XX is PP-generated if for any subset AXA\subset X that is not open in XX there is a subspace YXY \subset X with property PP such that AYA\cap Y is not open in YY. (Of course, in this definition we could replace "open" with "closed".) In this paper we prove the following two results: (1) Every Lindel\"of-generated regular space XX satisfying X=Δ(X)=ω1|X|=\Delta(X)={\omega}_1 is ω1{\omega}_1-resolvable. (2) Any (countable extent)-generated regular space XX satisfying Δ(X)>ω\Delta(X)>{\omega} is ω{\omega}-resolvable. These are significant strengthenings of our earlier results from [JSSz] which can be obtained from (1) and (2) by simply omitting the "-generated" part. Moreover, the second result improves a recent result of Filatova and Osipov from [FO] which states that Lindel\"of-generated regular spaces of uncountable dispersion character are 2-resolvable. [FO] Maria A. Filatova, Alexander V. Osipov On resolvability of Lindel\"of generated spaces, arxiv:1712.00803. Siberian Electronic Mathematical Reports, Vol. 14, (2017) pp. 1444-1444. [JSSz] Juh\'asz, Istv\'an; Soukup, Lajos; Szentmikl\'ossy, Zolt\'an, Regular spaces of small extent are ω{\omega}-resolvable. Fund. Math. 228 (2015), no. 1, 27-46.

Keywords

Cite

@article{arxiv.1804.03019,
  title  = {On the resolvability of Lindel\"of-generated and (countable extent)-generated spaces},
  author = {István Juhász and Lajos Soukup and Zoltán Szentmiklóssy},
  journal= {arXiv preprint arXiv:1804.03019},
  year   = {2018}
}

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12 pages