On the Number of Normal Measures אּ1 and אּ2 can CarryArthur 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 אּ1
and אּ2 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 אּ1 | x contains a club set}, and אּ2 will carry
exactly t normal measures, where t ³ אּ3
is any regular cardinal. This contrasts with the well-known facts that assuming AD + DC, אּ1 is measurable and carries exactly one normal measure, and
אּ2 is measurable and carries exactly two normal measures.
Tbilisi Mathematical Journal, Vol. 1(2008), pp. 9-14 |