Abstract
The cardinal invariants h, b, s of P(ω) are known to satisfy that ω1 ≤ h ≤ min{b, s}. We prove that all inequalities can be strict. We also introduce a new upper bound for h and show that it can be less than s. The key method is to utilize finite support matrix iterations of ccc posets following paper Ultrafilters with small generating sets by A. Blass and S. Shelah (1989).
Original language | English |
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Pages (from-to) | 331-351 |
Number of pages | 21 |
Journal | Commentationes Mathematicae Universitatis Carolinae |
Volume | 64 |
Issue number | 3 |
DOIs | |
State | Published - 2023 |
Bibliographical note
Publisher Copyright:© (2023), (Charles University, Faculty of Mathematics and Physics). All rights reserved.
Keywords
- cardinal invariants of the continuum
- matrix forcing