2024/10/11 by Jonathan Cancino-Manríquez, Jindrich Zapletal, Cancino-Manríquez, Jonathan +1 · 2 citations
Mathematics · #FOS: Mathematics #Logic (math.LO) #Mathematics and Applications #Point processes and geometric inequalities
paper · pdf · doi:10.48550/arxiv.2410.08699
openalex publication_date 2024/10/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present three models concerning Tukey types of ultrafilters on ω. The first model is built via a countable support iteration, and we show there is no basically generated ultrafilter in such model. The second and third models are built upon different and novel techniques, and in such models all ultrafilters are Tukey top, thus providing an answer to the Isbell problem. In all models there is no nwd-ultrafilter.