3 citations · 3 across the 7 of their papers we have counts for
8 papers
When surjectivity demands pathology
Piotr Kasprzak, Piotr Maćkowiak
In this paper, we characterize surjective nonlinear composition operators acting between the space of sequences of bounded variation and the space of bounded sequences. We show tha…
On the independence of axioms for measures of non-compactness
Jerzy Grzybowski, Piotr Kasprzak, Piotr Maćkowiak
We investigate the independence of the axioms in the Banaś--Goebel approach to the theory of measures of non-compactness. We present a complete answer for four of the five axioms.…
Hyperconvexity in partial metric spaces: challenges and outlooks
Dariusz Bugajewski, Piotr Kasprzak, Olivier Olela-Otafudu
In this article, we present several different ways to define hyperconvexity in partial metric spaces. In particular, we show that the analogue of the Aronszajn--Panitchpakdi notion…
Integral operators in the spaces of functions of bounded Schramm variation
Jacek Gulgowski, Piotr Kasprzak, Piotr Maćkowiak
In this paper we provide a full characterization of linear integral operators acting from the space of functions of bounded Jordan variation to the space of functions of bounded Sc…
Compactness in Lipschitz spaces and around
Jacek Gulgowski, Piotr Kasprzak, Piotr Maćkowiak
The aim of the paper is to characterize (pre)compactness in the spaces of Lipschitz/Hölder continuous mappings acting from a compact metric space to a normed space. To this end som…
Compactness in normed spaces: a unified approach through semi-norms
Jacek Gulgowski, Piotr Kasprzak, Piotr Maćkowiak
In this paper we prove two new abstract compactness criteria in normed spaces. To this end we first introduce the notion of an equinormed set using a suitable family of semi-norms…
Integrate-and-fire models with an almost periodic input function
Piotr Kasprzak, Adam Nawrocki, Justyna Signerska-Rynkowska
We investigate leaky integrate-and-fire models (LIF models for short) driven by Stepanov and -almost periodic functions. Special attention is paid to the properties of a firing…
Solvability of Hammerstein integral equations with applications to boundary value problems
Daria Bugajewska, Gennaro Infante, Piotr Kasprzak
In this paper we present some new results regarding the solvability of nonlinear Hammerstein integral equations in a special cone of continuous functions. The proofs are based on a…