On the Number of Normal Measures אּ1 and אּ2 can Carry

Arthur W. Apter

We show that assuming the consistency of certain large cardinals (namely a supercompact cardinal with a measurable cardinal above it), it is possible to force and construct choiceless universes of ZF in which the first two uncountable cardinals 1 and 2 are both measurable and carry certain fixed numbers of normal measures. Specifically, in the models constructed, will carry exactly one normal measure, namely mw = {x Í 1 | x contains a club set}, and 2 will carry exactly t normal measures, where t ³ 3 is any regular cardinal. This contrasts with the well-known facts that assuming AD + DC, 1 is measurable and carries exactly one normal measure, and 2 is measurable and carries exactly two normal measures.

Tbilisi Mathematical Journal, Vol. 1(2008), pp. 9-14