activity
20202026
most citedOn density of compactly supported smooth functions in fractional Sobolev spaces

19 citations · 54 across the 11 of their papers we have counts for

collaborators

13 papers

math.AP2026

Hardy-Sobolev-Maz'ya inequalities for

Avas Banerjee, Michał Kijaczko, Vivek Sahu

We establish Hardy--Sobolev--Maz'ya inequalities in the subquadratic range for singularities supported on affine subspaces and for arbitrary domains. We first prove a Hardy…

math.AP2026

Fractional Hardy--Maz'ya inequality on a half-space

Michał Kijaczko, Antoni Szczukiewicz

The main purpose of this article is to provide a fractional counterpart of the well-known Maz'ya inequality on the half-space, that is $$ \int_{\mathbb{R}^{d}_{+}}\int_{\mathbb{R}^…

math.AP2025

Best constants for Hardy inequalities in Triebel--Lizorkin spaces

Michał Kijaczko

We find sharp constants in fractional Hardy inequalities for weighted Triebel--Lizorkin seminorms on the whole space and half-spaces. Our results generalize recently obtained weigh…

math.AP2025★ 1 cited

Weighted fractional Hardy-Sobolev and Hardy-Sobolev-Maz'ya inequalities with singularities on flat submanifold

Michał Kijaczko, Vivek Sahu

We investigate the sharp constant for weighted fractional Hardy inequalities with the singularity on a flat submanifold of codimension , where . We also prove a weigh…

math.CA2024

Improved Hardy and Rellich inequalities for antisymmetric and odd functions

Michał Kijaczko

We investigate the Hardy and Rellich inequalities for classes of antisymmetric and odd functions and general exponent . The obtained constants are better than the classical ones…

math.AP2023★ 2 cited

Asymptotics of weighted Gagliardo seminorms

Michał Kijaczko

In this paper we consider fractional Sobolev spaces equipped with weights being powers of the distance to the boundary of the domain. We prove the versions of Bourgain--Brezis--Mir…

math.PR2023

Shot-down stable processes

Krzysztof Bogdan, Kajetan Jastrzȩbski, Moritz Kassmann +2

The shot-down process is a strong Markov process which is annihilated, or shot down, when jumping over or to the complement of a given open subset of a vector space. Due to specifi…

math.AP2023★ 4 cited

Sharp fractional Hardy inequalities with a remainder for

Bartłomiej Dyda, Michał Kijaczko

The main purpose of this article is to obtain (weighted) fractional Hardy inequalities with a remainder and fractional Hardy-Sobolev-Maz'ya inequalities valid for .

math.AP2022★ 11 cited

Sharp weighted fractional Hardy inequalities

Bartłomiej Dyda, Michał Kijaczko

We investigate the weighted fractional order Hardy inequality $$ \int_Ω\int_Ω\frac{|f(x)-f(y)|^{p}}{|x-y|^{d+sp}}\text{dist}(x,\partialΩ)^{-α}\text{dist}(y,\partialΩ)^{-β}\,dy\,dx\…

math.AP2021★ 5 cited

Fractional Sobolev spaces with power weights

Michał Kijaczko

We investigate the form of the closure of the smooth, compactly supported functions in the weighted fractional Sobolev space for bounded .…

math.AP2021★ 4 cited

Sharp Hardy inequalities for Sobolev-Bregman forms

Michał Kijaczko, Julia Lenczewska

We obtain sharp fractional Hardy inequalities for the half-space and for convex domains. We extend the results of Bogdan and Dyda and of Loss and Sloane to the setting of Sobolev-B…

math.AP2021★ 19 cited

On density of compactly supported smooth functions in fractional Sobolev spaces

Bartłomiej Dyda, Michał Kijaczko

We describe some sufficient conditions, under which smooth and compactly supported functions are or are not dense in the fractional Sobolev space for an open, bounded…

math.AP2020★ 8 cited

On density of smooth functions in weighted fractional Sobolev spaces

Bartłomiej Dyda, Michał Kijaczko

We prove that smooth functions are dense in weighted fractional Sobolev spaces on an arbitrary open set, under some mild conditions on the weight. We also obtain a~simil…