Abstract
We analyze the effect of singularizing cardinals on square properties. By work of Džamonja-Shelah and of Gitik, if you singularize an inaccessible cardinal to countable cofinality while preserving its successor, then □κ,ω holds in the bigger model. We extend this to the situation where every regular cardinal in an interval [κ, ν] is singularized, for some regular cardinal ν. More precisely, we show that if V ⊂ W, κ < ν are cardinals, where ν is regular in V, κ is a singular cardinal in W of countable cofinality, cfW (τ) = ω for all V -regular κ ≤ τ ≤ ν, and (ν+)V = (κ+)W, then W |= □κ,ω.
Original language | English |
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Pages (from-to) | 4971-4980 |
Number of pages | 10 |
Journal | Proceedings of the American Mathematical Society |
Volume | 145 |
Issue number | 11 |
DOIs | |
State | Published - 2017 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2017 American Mathematical Society.