activity
20172026
most citedVector valued estimates for matrix weighted maximal operators and product

1 citations · 1 across the 12 of their papers we have counts for

collaborators

14 papers

math.PR2026

A stochastic Carleson embedding theorem with constant and the vector of Riesz transforms

Komla Domelevo, Johanna Fladung, Spyridon Kakaroumpas +2

We prove a continuous-time Carleson embedding theorem with constant for a system of square-integrable continuous martingales whose quadratic covariations mimic the generalised…

math.FA2026

Compact sets in quasi-Banach function spaces and multilinear extrapolation of compactness on

Spyridon Kakaroumpas, Stefanos Lappas

This paper addresses a novel Riesz--Kolmogorov theorem on quasi-Banach function spaces under mild conditions and the extrapolation of multilinear compact operators in the context o…

math.CA2026

The Poisson Matrix characteristic and the 3/2 blow up of the Hilbert transform

Komla Domelevo, Spyridon Kakaroumpas, Stefanie Petermichl +2

Recently the matrix conjecture was disproved. Indeed, the growth of the vector Hilbert transform in the matrix weighted space was shown to be at best a constant mult…

math.CA2025

Extrapolation for bilinear compact operators in the variable exponent setting

Spyridon Kakaroumpas, Stefanos Lappas

We establish extrapolation of compactness for bilinear operators in the scale of weighted variable exponent Lebesgue spaces. First, we prove an abstract principle relying on the Co…

math.FA2024

Multilinear matrix weights

Spyridon Kakaroumpas, Zoe Nieraeth

In this work we fully characterize the classes of matrix weights for which multilinear Calderón-Zygmund operators extend to bounded operators on matrix weighted Lebesgue spaces. To…

math.FA2024★ 1 cited

Vector valued estimates for matrix weighted maximal operators and product

Spyridon Kakaroumpas, Odí Soler i Gibert

We consider maximal operators acting on vector valued functions, that is, functions taking values on that incorporate matrix weights in their definitions. We show v…

math.CA2024

Matrix-weighted estimates beyond Calderón-Zygmund theory

Spyridon Kakaroumpas, Thu Hien Nguyen, Dimitris Vardakis

We investigate matrix-weighted bounds for the sublinear non-kernel operators considered by F. Bernicot, D. Frey, and S. Petermichl. We extend their result to sublinear operators ac…

math.CA2023

Matrix-weighted little BMO spaces in two parameters

Spyridon Kakaroumpas, Odí Soler i Gibert

In this paper we set up a theory of two-matrix weighted little BMO in two parameters. We prove that being a member of this class is equivalent to belonging uniformly in each variab…

math.CV2023

Preimages under linear combinations of iterates of finite Blaschke products

Spyridon Kakaroumpas, Odí Soler i Gibert

Consider a finite Blaschke product with which is not a rotation and denote by its -th iterate. Given a sequence of complex numbers, consider the s…

math.CA2021

Boundedness of Journé operators with matrix weights

Komla Domelevo, Spyridon Kakaroumpas, Stefanie Petermichl +1

We develop a biparameter theory for matrix weights and provide various biparameter matrix-weighted bounds for Journé operators as well as other central operators under the assumpti…

math.CA2020

Dyadic product BMO in the Bloom setting

Spyridon Kakaroumpas, Odí Soler i Gibert

Ó. Blasco and S. Pott showed that the supremum of operator norms over of all bicommutators (with the same symbol) of one-parameter Haar multipliers dominates the biparameter…

math.CA2019

Two-weight estimates for sparse square functions and the separated bump conjecture

Spyridon Kakaroumpas

We show that two-weight bounds for sparse square functions, uniformly with respect to the sparseness constant of the underlying sparse family, and in both directions, do not…

math.CA2018

"Small step" remodeling and counterexamples for weighted estimates with arbitrarily "smooth" weights

Spyridon Kakaroumpas, Sergei Treil

For an weight the norm of the Hilbert Transform in , is estimated by , where is the characteristic of the weight …

math.CA2017

A note on a two-weight estimate for the dyadic square function

Spyridon Kakaroumpas

We show that the two-weight estimate for the dyadic square function proved by Lacey--Li in [2] is sharp.