activity
19992003
most citedThere may be no Hausdorff ultrafilters

3 citations · 3 across the 3 of their papers we have counts for

collaborators
Showing 1999Show all

15 papers · 1 filter

math.LO1999

Invariants of Measure and Category

Tomek Bartoszynski

A survey of recent results concerning cardinal invariants of measure and category. Submitted as a chapter of the upcoming Handbook of Set Theory.

math.LO1999

Strongly meager and strong measure zero sets

Tomek Bartoszynski, Saharon Shelah

We show that the following are consistent with ZFC: 1. Strongly meager sets form an ideal with the same additivity as the ideal of meager sets. 2. There exists a strong measure zer…

math.LO1999

On the structure of measurable filters on a countable set

Tomek Bartoszynski

A combinatorial characterization of measurable filters on a countable set is found. We apply it to the problem of measurability of the intersection of nonmeasurable filters.

math.LO1999

Closed measure zero sets

Tomek Bartoszynski, Saharon Shelah

We study the relationship between the sigma-ideal generated by closed measure zero sets and the ideals of null and meager sets. We show that the additivity of the ideal of closed m…

math.LO1999

The Cichon diagram

Tomek Bartoszynski, Haim Judah, Saharon Shelah

We conclude the discussion of additivity, Baire number, uniformity and covering for measure and category by constructing the remaining 5 models. Thus we complete the analysis of Ci…

math.LO1999

A-sets

Tomek Bartoszynski, Marion Scheepers

We consider ``meager analogues'' of classical covering properties of Menger, Hurewicz and Rothberger. We show that Borel images of sets having ``our'' covering properties have thes…