Rapid ultrafilters and summable ideals
Abstract
This note answers the following question: Is it consistent that for an arbitrary tall summable ideal Ig there exists an Ig-ultrafilter which is not rapid? We show that assuming Martin's Axiom for σ-centered posets such ultrafilters exist for each tall summable ideal Ig.
0
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.