Some Remarks on Normal Measures and Measurable Cardinals
Abstract
We prove two theorems which in a certain sense show that the number of normal measures a measurable cardinal κ can carry is independent of a given fixed behavior of the continuum function on any set having measure 1 with respect to every normal measure over κ . First, starting with a model V ⊨ “ZFC + GCH + o = δ*” for δ* ≤ κ+ any finite or infinite cardinal, we force and construct an inner model N ⊆ V [G] so thatN ⊨ “ZF + [DCδ] + ¬ACκ + κ carries exactly δ* normal measures + 2δ = δ++ on a set having measure 1 with respect to every normal measure over κ”.There is nothing special about 2δ = δ here, and other stated values for the continuum function will be possible as well. Then, starting with a modelV ⊨ “ZFC + GCH + κis supercompact”,we force and construct models of AC in which, roughly speaking, regardless of the specified behavior of the continuum function below κ on any set having measure 1 with respect to every normal measure over κ, κ can in essence carry any number of normal measures δ* ≥ κ++