6 citations · 12 across the 4 of their papers we have counts for
4 papers
New Hindman spaces
Rafał Filipów, Krzysztof Kowitz, Adam Kwela +1
We introduce a method that allows to turn topological questions about Hindman spaces into purely combinatorial questions about the Katětov order of ideals on . We also…
Characterizing existence of certain ultrafilters
Rafał Filipów, Krzysztof Kowitz, Adam Kwela
Following Baumgartner [J. Symb. Log. 60 (1995), no. 2], for an ideal on , we say that an ultrafilter on is an -ultrafilter if for ev…
A unified approach to Hindman, Ramsey and van der Waerden spaces
Rafał Filipów, Krzysztof Kowitz, Adam Kwela
For many years, there have been conducting research (e.g. by Bergelson, Furstenberg, Kojman, Kubiś, Shelah, Szeptycki, Weiss) into sequentially compact spaces that are, in a sense,…
Katětov order between Hindman, Ramsey, van der Waerden and summable ideals
Rafał Filipów, Krzysztof Kowitz, Adam Kwela
A family I of subsets of a set X is an ideal on X if it is closed under taking subsets and finite unions of its elements. An ideal I on X is below an ideal J on Y in the Katetov or…