Tukey classes of ultrafilters on omega

Details Tukey classes of ultrafilters on omega Tukey classes of ultrafilters on omega

2008-07-25

arxiv.org/abs/0807.3978v1

Topology Proceedings 32 (2008) 351--362

Mathematics

Logic

8 pages

Scientific paper

Motivated by a question of Isbell, we show that Jensen's Diamond Principle implies there is a non-P-point ultrafilter U on omega such that U, whether ordered by reverse inclusion or reverse inclusion mod finite, is not Tukey equivalent to the finite sets of reals ordered by inclusion. We also show that, for every regular infinite kappa not greater than 2^{aleph_0}, if MA_{sigma-centered} holds, then some ultrafilter U on omega, ordered by reverse inclusion mod finite, is Tukey equivalent to the sets of reals of size less than kappa, ordered by inclusion. We also prove two negative ZFC results about the possible Tukey classes of ultrafilters on omega.

Affiliated with

Also associated with

No associations

Rating

Tukey classes of ultrafilters on omega does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Tukey classes of ultrafilters on omega, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tukey classes of ultrafilters on omega will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-324961