hm and the ultrafilter number
Speaker:
Osvaldo Guzman, York University
Date and Time:
Friday, May 11, 2018 - 1:30pm to 3:00pm
Abstract:
The cardinal invariant hm is defined as the minimum size of a family of cmin-monochromatic sets that cover 2ω (where cmin(x,y) is the parity of the biggest initial segment both x and y have in common). We prove that hm=ω1 holds in the Shelah's model of i<u so the inequality hm<u is consistent with the axioms of ZFC. This answers a question of Thilo Weinert.