Better closed ultrafilters on \(\mathbb{Q}{}\)
type: Item
instance of: scholarly article
title: Better closed ultrafilters on \(\mathbb{Q}{}\)
zbMATH Open document ID: 0786.54023
DOI: 10.1016/0166-8641(92)90028-X
author: Eric K. van Douwen
published in: Topology and its Applications
publication date: 1993-04-01T00:00:00Z
review text: Using MA for countable posets, the author proves, for each \(n\in\mathbb{N}\), there is a free closed ultrafilter \(\alpha\) on \(\mathbb{Q}\) such that (1) if \(K\) is a closed, scattered subspace of \(\mathbb{Q}\), there is some \(F\in\alpha\) such that \(F\cap K=\emptyset\), and (2) \(\{\beta\): \(\beta\) is an ultrafilter on \(\mathbb{Q}\) and \(\alpha\subseteq\beta\}\) has size \(n\).
Mathematics Subject Classification ID: 54D35
zbMATH DE Number: 149079
zbMATH Keywords: Stone-Čech compactification
zbMATH Keywords: remainders
zbMATH Keywords: rational numbers
zbMATH Keywords: ultrafilter
MaRDI profile type: Publication
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description: scientific article; zbMATH DE number 149079