3 citations · 4 across the 5 of their papers we have counts for
5 papers
A Levin-Milman theorem for Young variation
N. G. Albuquerque, D. Bugajewska, E. Demétrio +1
In 1940, Levin\footnotemark[1] and Milman proved that a closed linear subspace of whose elements all have bounded Jordan variation must be finite-dimensional. We prove its…
Nonlinear composition operators in bv_p spaces: continuity and compactness
Daria Bugajewska, Piotr Kasprzak
Continuing the study initiated in our earlier article [7], this paper aims to characterize various continuity properties of nonlinear composition operators acting on some sequence…
Composition operators in -spaces, part I: acting conditions and boundedness
Daria Bugajewska, Piotr Kasprzak
The aim of this paper is to give the answer to the problem of characterization of acting conditions (necessary as well as sufficient) for composition operators in some sequence spa…
Josephy's theorem, revisited
Daria Bugajewska, Piotr Kasprzak
The main goal of this note is to characterize the necessary and sufficient conditions for a composition operator to act between spaces of mappings of bounded Wiener variation in a…
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…