2025/12/08 by Balderas, Emmanuel, Chodounský, David, Guzmán, Osvaldo
#FOS: Mathematics #Logic (math.LO)
paper · doi:10.48550/arxiv.2512.08081
In this paper, we study a special type of ultrafilter which we call Shelah ultrafilter. We show that it is possible to add a Shelah ultrafilter using a special forcing notion. We also show that Shelah ultrafilters turn out to be I-ultrafilters for many Borel ideals.