Loading Web-Font TeX/Main/Regular
| Register
\newcommand{\Cat}{{\rm Cat}} \newcommand{\A}{\mathcal A} \newcommand{\freestar}{ \framebox[7pt]{$\star$} }

6. Precipitouness of NS

    1. Problem 6.4.

      [Larson] Assume \text{NS}_{\omega_1} is precipitous. Is it possible to force \text{NS}_{\omega_1} to be non-precipitous without adding subsets of \omega_1?
        1. Remark. [Larson] It is consistent for this to be impossible, e.g. if NS_{\omega_1}^+ has a dense subset of size \aleph_1. Also, any such forcing must always add a subset of size \omega_1?

              Cite this as: AimPL: From ℵ2 to infinity, available at http://aimpl.org/alephtwo.