8 papers · 1 filter
A note on asymptotic density
Ryszard Frankiewicz, Joanna Jureczko
It is proved that , where is the ideal of sets of asymptotic density zero, is universal in the sense of embeddings.
Equivalence of the existence of K-partitions with the existence of the precipitous ideal
Ryszard Frankiewicz, Joanna Jureczko
In this note we give equivalence of the existence of K-partitions with the existence of the precipitous ideal which is essentially topological. This way we strengthen the main resu…
Partitions of non-complete Baire metric spaces
Ryszard Frankiewicz, Joanna Jureczko
We investigate the properties of ideals associated with Kuratowski partitions of non-complete Baire metric spaces. We show that such an ideal can be precipitous.
On special partitions of metric spaces
Ryszard Frankiewicz, Joanna Jureczko
The main result of this paper is to show that, if is the smallest real-valued measurable cardinal not greater than , then there exists a complete metric space of…
On Kuratowski partitions
Ryszard Frankiewicz, Joanna Jureczko
In 1935 K. Kuratowski posed the problem whether a function f:X ! Y , (X is completely metrizable and Y is metrizable), with the property that a preimage of each open has the Baire…
A short mathematical proof of Frankiewicz - Kunen theorem
Ryszard Frankiewicz, Joanna Jureczko
In this paper there is proved without any metamathematical techniques that the existence of precipitous ideals immediately follows from Kuratowski partitions.