Piotr Borodulin-Nadzieja

activity

20112026

most citedSequential closure in the space of measures

3 citations · 3 across the 15 of their papers we have counts for

collaborators

19 papers

math.FA2026

Geometric duality, perfect graphs, and the Sierpiński space

Piotr Borodulin-Nadzieja, Barnabás Farkas, Anna Pelczar-Barwacz

In their classical paper \emph{On the stopping time Banach space}, Bang and Odell, among a plethora of results concerning the dyadic stopping time space and its dual, presented the…

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 $ω$ . We propose a generalization of the notion of Q-point and selective ultrafilter to…

math.FA2024

The ZOO of combinatorial Banach spaces

Piotr Borodulin-Nadzieja, Barnabás Farkas, Sebastian Jachimek +1

We study Banach spaces induced by families of finite sets in the most natural (Schreier-like) way, that is, we consider the completion $X_\mc{F}$ of $c_{00}$ with respect to the no…

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,…

math.LO2023

On points avoiding measures

Piotr Borodulin-Nadzieja, Artsiom Ranchynski

We say that an element $x$ of a topological space $X$ avoids measures if for every Borel measure $μ$ on $X$ if $μ ({x}) = 0$ , then there is an open $U ∋ x$ such that $μ (U) = 0$ . The…

math.FA2022

On the spaces dual to combinatorial Banach spaces

Piotr Borodulin-Nadzieja, Sebastian Jachimek, Anna Pelczar-Barwacz

We present quasi-Banach spaces which are closely related to the duals of combinatorial Banach spaces. More precisely, for a compact family $F$ of finite subsets of $ω$ we…

math.LO2022

There is a P-measure in the random model

Piotr Borodulin-Nadzieja, Damian Sobota

We say that a finitely additive probability measure $μ$ on $ω$ is \emph{a P-measure} if it vanishes on points and for each decreasing sequence $(E_{n})$ of infinite subsets of $ω$ th…

math.LO2021

On measures induced by forcing names for ultrafilters

Piotr Borodulin-Nadzieja, Katarzyna Cegiełka

We study the interplay between properties of measures on a Boolean algebra A and forcing names for ultrafilters on A. We show that several well known measure theoretic properties o…

math.LO2021

On sequences of homomorphisms into measure algebras and the Efimov Problem

Piotr Borodulin-Nadzieja, Damian Sobota

For given Boolean algebras $A$ and $B$ we endow the space $H (A, B)$ of all Boolean homomorphisms from $A$ to $B$ with…

math.LO2019

Splitting chains, tunnels and twisted sums

Félix Cabello Sánchez, Antonio Avilés, Piotr Borodulin-Nadzieja +2

We study splitting chains in $P (ω)$ , that is, families of subsets of $ω$ which are linearly ordered by $\subseteq^{*}$ and which are splitting. We prove that their existenc…

math.LO2019

Analytic P-ideals and Banach spaces

Piotr Borodulin-Nadzieja, Barnabás Farkas

We study the interplay between Banach space theory and theory of analytic P-ideals. Applying the observation that, up to isomorphism, all Banach spaces with unconditional bases can…

math.LO2016

On non-separable growths of omega supporting measures

Piotr Borodulin-Nadzieja, Tomasz Żuchowski

We present several $ZFC$ examples of compactifications $γ ω$ of $ω$ such that their remainders $γ ω \ ω$ are nonseparable and carry strictly positive measures.

math.LO2016

Measures and slaloms

Piotr Borodulin-Nadzieja, Tanmay Inamdar

We examine measure-theoretic properties of spaces constructed using certain technique of Todorčević. We show that the existence of strictly positive measures on such spaces depends…

math.LO2016

Measures and fibers

Piotr Borodulin-Nadzieja

We study measures on compact spaces by analyzing the properties of fibers of continuous mappings into 2^omega. We show that if a compact zerodimensional space K carries a measure o…

math.LO2015

Measures on Suslinean spaces

Piotr Borodulin-Nadzieja, Grzegorz Plebanek

We study the existence of non-separable compact spaces that support a measure and are small from the topological point of view. In particular, we show that under Martin's axiom the…

math.LO2014

Representations of ideals in Polish groups and in Banach spaces

Piotr Borodulin-Nadzieja, Barnabas Farkas, Grzegorz Plebanek

We investigate ideals of the form ${A \subseteq ω : \sum_{n \in A} x_{n}$ is unconditionally convergent $}$ , where $(x_{n})_{n \in ω}$ is a sequence in a Polish group or in a Banach…

math.LO2013

Hausdorff gaps and towers in P(ω)/Fin

Piotr Borodulin-Nadzieja, David Chodounský

We define and study two classes of uncountable $\subseteq^{*}$ -chains: Hausdorff towers and Suslin towers. We discuss their existence in various models of set theory. Then, some of t…

math.GN2012★ 3 cited

Sequential closure in the space of measures

Piotr Borodulin-Nadzieja, Omar Selim

We show that there is a compact topological space carrying a measure which is not a weak* limit of finitely supported measures but is in the sequential closure of the set of such m…

math.LO2011

On the isomorphism problem for measures on Boolean algebras

Piotr Borodulin-Nadzieja, Mirna Džamonja

The paper investigates possible generalisations of Maharam's theorem to a classification of Boolean algebras that support a finitely additive measure. We prove that Boolean algebra…