Ultrafilters with small generating sets

Research paper by Andreas Blass, Saharon Shelah

Indexed on: 01 Oct '89Published on: 01 Oct '89Published in: Israel Journal of Mathematics


It is consistent, relative to ZFC, that the minimum number of subsets ofω generating a non-principal ultrafilter is strictly smaller than the dominating number. In fact, these two numbers can be any two prescribed regular cardinals.