English

Selection Principles for Measurable Functions and Covering Properties

General Topology 2020-01-01 v1

Abstract

Let AP(X){\mathcal A}\subset {\mathcal P}(X), ,XA\emptyset, X\in {\mathcal A}, A{\mathcal A} being closed under finite intersections. If ψ=o,ω,γ\psi={o},\omega,\gamma, then Ψ(A)\Psi({\mathcal A}) is the family of those ψ\psi-covers U{\mathcal U} for which UA{\mathcal U}\subseteq {\mathcal A}. In~\cite{BL2} I have introduced properties (Ψ0(\Psi_0 of a~family FXRF\subseteq {}^XR of real functions. The main result of the paper Theorem reads as follows: if~Φ=Ω,Γ\Phi=\Omega,\Gamma, then for any couple Φ,Ψ\langle \Phi,\Psi\rangle different from Ω,O\langle \Omega,{\mathcal O}\rangle, XX has the covering property~{\rm S}1(Φ(A),Ψ(A)){}_1(\Phi({\mathcal A}),\Psi({\mathcal A})) if and only if the family of non-negative upper A{\mathcal A}-semimeasurable real functions satisfies the selection principle~{\rm S}1(Φ0,Ψ0){}_1(\Phi_0,\Psi_0). Similarly for {\rm S}fin{}_{\scriptstyle fin} and {\rm U}fin{}_{\scriptstyle fin}. Some related results are also presented.

Keywords

Cite

@article{arxiv.1912.12441,
  title  = {Selection Principles for Measurable Functions and Covering Properties},
  author = {Lev Bukovský},
  journal= {arXiv preprint arXiv:1912.12441},
  year   = {2020}
}

Comments

21 pages

R2 v1 2026-06-23T12:57:58.943Z