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20222026
most citedComposition operators on weighted Hilbert spaces of Dirichlet series

8 citations · 14 across the 9 of their papers we have counts for

collaborators

11 papers

math.CA2026

Mean values, order, and convergence in the Hardy space of Dirichlet series

Ole Fredrik Brevig, Athanasios Kouroupis

Let denote the Hilbert space of Dirichlet series with square-summable coefficients. It follows from a theorem of Bohr that if in has a bounded a…

math.CA2026

Harald Bohr's splitting theorem

Viktor Andersson, Ole Fredrik Brevig, Athanasios Kouroupis

We present a new elementary proof of a theorem due to Harald Bohr, which states that an unbounded, analytic, and almost periodic function in a half-plane can be written as the sum…

math.CA2025

Carlson's theorem and vertical limit functions

Ole Fredrik Brevig, Athanasios Kouroupis

We extend a classical theorem of Carlson on moments of Dirichlet series from to . When combined with the ergodic theorem for the Kronecker flow, a coherent…

math.CV2024

Brennan's conjecture holds for semigroups of holomorphic functions

Alexandru Aleman, Athanasios Kouroupis

In the present note, we give a short proof of Brennan's conjecture in the special case of continuous semigroups of holomorphic functions. We apply classical techniques of complex a…

math.CA2024

Almost periodicity and boundary values of Dirichlet series

Ole Fredrik Brevig, Athanasios Kouroupis, Karl-Mikael Perfekt

We employ almost periodicity to establish analogues of the Hardy--Stein identity and the Littlewood--Paley formula for Hardy spaces of Dirichlet series. A construction of Saksman a…

math.CV2024

On universality of general Dirichlet series

Frédéric Bayart, Athanasios Kouroupis

In the present work, we establish sufficient conditions for a Dirichlet series induced by general frequencies to be universal with respect to vertical translations. Our results can…

math.FA2023★ 2 cited

Schatten class composition operators on the Hardy space of Dirichlet series and a comparison-type principle

Frédéric Bayart, Athanasios Kouroupis

We give necessary and sufficient conditions for a composition operator with Dirichlet series symbol to belong to the Schatten classes of the Hardy space of Di…

math.CV2023★ 4 cited

An extension of Bohr's theorem

Ole Fredrik Brevig, Athanasios Kouroupis

The following extension of Bohr's theorem is established: If a somewhere convergent Dirichlet series has an analytic continuation to the half-plane $\mathbb{C}_θ= \{s = σ+it\,:…

math.NT2023

A note on Bohr's theorem for Beurling integer systems

Frederik Broucke, Athanasios Kouroupis, Karl-Mikael Perfekt

Given a sequence of frequencies , a corresponding generalized Dirichlet series is of the form . We are interested in multiplicati…

math.FA2022

Composition operators and generalized primes

Athanasios Kouroupis

We study composition operators on the Hardy space of Dirichlet series with square summable coefficients. Our main result is a necessary condition, in terms of a Nev…

math.FA2022★ 8 cited

Composition operators on weighted Hilbert spaces of Dirichlet series

Athanasios Kouroupis, Karl-Mikael Perfekt

We study composition operators of characteristic zero on weighted Hilbert spaces of Dirichlet series. For this purpose we demonstrate the existence of weighted mean counting functi…