Range of values for ##2^{\aleph_0}##

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 2K views
Messages
7,828
Reaction score
13,156
TL;DR
Possible values of cardinality in different models of ZFC+ ~CH
Ok, so assume we have a model for ZFC where CH does not hold. What values may ##2^{\aleph_0}## assume over said models?
 
Physics news on Phys.org
According to Wikipedia,

A result of Solovay, proved shortly after Cohen's result on the independence of the continuum hypothesis, shows that in any model of ZFC, if ##\kappa## is a cardinal of uncountable cofinality, then there is a forcing extension in which ##2^{\aleph_0} = \kappa##. However, per König's theorem, it is not consistent to assume ##2^{\aleph _{0}}## is ##\aleph _{\omega }## or ##\aleph _{\omega _{1}+\omega }## or any cardinal with cofinality ##\omega##.
 
Reply
  • Like
Likes   Reactions: WWGD