ω1 can be measurable
暂无分享,去创建一个
It is shown that ifZF + the axiom of choice + “there is a measurable cardinal” is consistent thenZF + “ω1 is measurable” is consistent. The corresponding model is a symmetric submodel of the Cohen-type extension which collapses the first measurable cardinal onto ω0.
[1] A. Levy,et al. Measurable cardinals and the continuum hypothesis , 1967 .
[2] Alfred Tarski,et al. From accessible to inaccessible cardinals (Results holding for all accessible cardinal numbers and the problem of their extension to inaccessible ones) , 1964 .
[3] Petr Vopěnka. General theory of $\nabla$-models , 1967 .