The Spectrum of Characters of Ultrafilters on Ω Sh846
نویسنده
چکیده
We show the consistency of statement: “the set of regular cardinals which are the character of some ultrafilter on ω is not convex”. We also deal with the set of π-characters of ultrafilters on ω.
منابع مشابه
The Combinatorics of Reasonable Ultrafilters
We are interested in generalizing part of the theory of ultrafilters on ω to larger cardinals. Here we set the scene for further investigations introducing properties of ultrafilters in strong sense dual to being normal. 0. Introduction A lot of knowledge has been accumulated on ultrafilters on ω. In the present paper we are interested in carrying out some of those arguments for ultrafilters on...
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