3 papers
math.FA2025
A small Radon-Nikodým compact space from a parametrized diamond
Arturo Martínez-Celis, Adam Morawski
A compact space is Radon-Nikodým if there is a lower semi-continuous metric fragmenting . In this note, we show that, under , there…
math.LO2025
On the Rudin-Blass Ordering of Measures
Piotr Borodulin-Nadzieja, Arturo Martínez-Celis, Adam Morawski +1
We study the Rudin-Blass (and the Rudin-Keisler) ordering on the finite additive measures on . We propose a generalization of the notion of Q-point and selective ultrafilter to…
math.LO2024
P-measures in models without P-points
Piotr Borodulin-Nadzieja, Jonathan Cancino-Manríquez, Adam Morawski
We answer in negative the problem if the existence of a P-measure implies the existence of a P-point. Namely, we show that if we add random reals to a certain unique P-point model,…