22 citations · 31 across the 9 of their papers we have counts for
10 papers
Characterized subgroups on the unit circle
Rafal Filipow, Adam kwela, Paolo Leonetti +1
Given an ideal on , a subgroup of the unit circle is said to be -characterized if there exists an integer sequence …
Compactness in spaces of functions of bounded variation from ideal perspective
Jacek Gulgowski, Adam Kwela, Jacek Tryba
Recently we have presented a unified approach to two classes of Banach spaces defined by means of variations (Waterman spaces and Chanturia classes), utilizing the concepts from th…
Path of pathology
Rafał Filipów, Jacek Tryba
We present a few results about (non)pathology of submeasures and ideals.
Functions of bounded variation from ideal perspective
Jacek Gulgowski, Adam Kwela, Jacek Tryba
We present a unified approach to two classes of Banach spaces defined with the aid of variations: Waterman spaces and Chanturia classes. Our method is based on some ideas coming fr…
Densities for sets of natural numbers vanishing on a given family
Rafał Filipów, Jacek Tryba
Abstract upper densities are monotone and subadditive functions from the power set of positive integers into the unit real interval that generalize the upper densities used in numb…
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…
The ideal test for the divergence of a series
Rafał Filipów, Adam Kwela, Jacek Tryba
We generalize the classical Olivier's theorem which says that for any convergent series with positive nonincreasing real terms the sequence tends to zero. Ou…
On the structure of Borel ideals in-between the ideals and in the Katětov order
Pratulananda Das, Rafał Filipów, Szymon Głąb +1
For a family we define the ideal on to be the ideal generated by the family $\{A\subseteq ω\timesω:\exists f\in \ma…
Properties of simple density ideals
Adam Kwela, Michał Popławski, Jarosław Swaczyna +1
Let consist of all functions with and . Then for each the family $\mathcal{Z}_g=\{A\subsete…
Homogeneous ideals on countable sets
Adam Kwela, Jacek Tryba
We say that an ideal I is homogeneous, if its restriction to any I-positive subset is isomorphic to I. The paper investigates basic properties of this notion -- we give examples of…