22 citations · 105 across the 33 of their papers we have counts for
39 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 …
Are scales Fréchet?
Raul Figueroa-Sierra, Osvaldo Guzmán, Michael Hrušák +1
We continue the study of Dow spaces of a -scale, originally introduced by Alan Dow in "-Weight and the Fréchet-Urysohn property" (Topology and its Applications, Vo…
A new order for ideal sequential compactness
Adam Kwela, Dorota Lesner
Let be an ideal on and be a topological space. A sequence in is -convergent if there is such that $\{n\in ω:x_n\not…
Sets of Ramsey-limit points and IP-limit points
Rafał Filipów, Adam Kwela, Paolo Leonetti
Let be an uncountable Polish space and let be the Hindman ideal, that is, the family of all which are not -sets. For each sequence $x=(x_n)_{n…
Critical partition regular functions for compact spaces
Rafał Filipów, Małgorzata Kowalczuk, Hubert Książek +2
We study ideal-based refinements of sequential compactness arising from the class FinBW(I), consisting of topological spaces in which every sequence admits a convergent subsequence…
Zoo of ideal Schauder basis
Adam Kwela, Jarosław Swaczyna
We investigate the notion of filter (equivalently: ideal) Schauder basis of a Banach space. We do so by providing bunch of new examples of such bases that are not the standard ones…
Two or not two ?
Rafał Filipów, Adam Kwela
The paper is devoted to comparison of two generalizations of the bounding number .
Critical ideals for compact spaces
Rafał Filipów, Małgorzata Kowalczuk, Adam Kwela
For each countable ordinal , we introduce an ideal and use it to characterize the class of all compact countable spaces which are homeomorphic to the space $ω^α\cdot n+…
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…
Borel complexity of sets of ideal limit points
Rafal Filipow, Adam Kwela, Paolo Leonetti
Let be an uncountable Polish space and let be an ideal on . A point is an -limit point of a sequence taking values in if ther…
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…
More on yet another ideal version of the bounding number
Adam Kwela
This is a continuation of the paper [J. Symb. Log. 87 (2022), 1065--1092]. For an ideal on we denote $\mathcal{D}_{\mathcal{I}}=\{f\inω^ω: f^{-1}[\{n\}]\in\mathca…
Egorov ideals
Adam Kwela
We study Egorov ideals, that is ideals on for which the Egorov's theorem for ideal versions of pointwise and uniform convergences holds. We show that a non-pathological $\bf{Σ^…
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…
Spaces not distinguishing ideal pointwise and -uniform convergence
Rafał Filipów, Adam Kwela
We examine topological spaces not distinguishing ideal pointwise and ideal -uniform convergence of sequences of real-valued continuous functions defined on them. For instance, w…
Yet another ideal version of the bounding number
Rafał Filipów, Adam Kwela
Let be an ideal on . For we write if for all with some . Moreover, we den…
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…
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…
Porosities of the sets of attractors
Paweł Klinga, Adam Kwela
This paper is another attempt to measure the difference between the family of attractors for iterated function systems acting on and a broader family, the set $A_w…
Comparison of the sets of attractors for systems of contractions and weak contractions
Paweł Klinga, Adam Kwela
For we consider the families: - of attractors for iterated function systems (IFS) consisting of contractions acting on , - of attra…
Borel complexity of the family of attractors for weak IFSs
Paweł Klinga, Adam Kwela
This paper is an attempt to measure the difference between the family of iterated function systems attractors and a broader family, the set of attractors for weak iterated function…
On a conjecture of Debs and Saint Raymond
Adam Kwela
Borel separation rank of an analytic ideal on is the minimal ordinal such that there is with $\mathcal{I}\subseteq \mathc…