On rapid idempotent ultrafilters
Logic
2013-05-07 v2
Abstract
This short note contains the proofs of two small but somewhat surprising results about ultrafilters on : 1. strongly summable ultrafilters are rapid, 2. every rapid ultrafilter induces a closed left ideal of rapid ultrafilters. As a consequence, there will be rapid minimal idempotents in all models of set theory with rapid ultrafilters.
Keywords
Cite
@article{arxiv.1304.3955,
title = {On rapid idempotent ultrafilters},
author = {Peter Krautzberger},
journal= {arXiv preprint arXiv:1304.3955},
year = {2013}
}