collaborators

6 papers

math.SP2026

Comparison inequalities for Dirichlet-to-Neumann maps

Denis S. Grebenkov, Michael Levitin, Karl-Mikael Perfekt +1

We prove comparison inequalities for Dirichlet-to-Neumann maps corresponding to different non-positive Helmholtz parameters. For convex domains our bounds are sharp, and the result…

math.FA2026

Recovering Product BMO from Schatten Hankel operators

Konstantinos Bampouras, Karl-Mikael Perfekt

We prove that if a small Hankel operator on the product Hardy space belongs to some Schatten class , , then it has a symbol in product BMO. In other words, the con…

math.CA2025

Restrictions of Békollé--Bonami weights and Bloch functions

Alberto Dayan, Adrián Llinares, Karl-Mikael Perfekt

We characterize the restrictions of Békollé--Bonami weights of bounded hyperbolic oscillation, to subsets of the unit disc, thus proving an analogue of Wolff's restriction theore…

math.FA2025

Besov spaces and Schatten class Hankel operators for Hardy and Paley--Wiener spaces in higher dimensions

Konstantinos Bampouras, Karl-Mikael Perfekt

We consider Schatten class membership of Hankel operators on Paley--Wiener spaces of convex , both for bounded and unbounded domains. In particular, the cla…

math.CA2025

Characterizations for arbitrary Békollé-Bonami weights

Carlos Mudarra, Karl-Mikael Perfekt

We precisely characterize the relationships between the reverse Hölder inequality, the Fujii-Wilson condition, the Békollé-Bonami condition, the $\mathrm{B}_\inft…

math.CA2025

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…