activity
20182022
most citedDeformations of Bi-conformal Energy and a new Characterization of Quasiconformality

12 citations · 17 across the 11 of their papers we have counts for

collaborators

12 papers

math.FA2022★ 3 cited

Extensions and approximations of Banach-valued Sobolev functions

Miguel García-Bravo, Toni Ikonen, Zheng Zhu

In complete metric measure spaces equipped with a doubling measure and supporting a weak Poincaré inequality, we investigate when a given Banach-valued Sobolev function defined on…

math.AP2022

Zero volume boundary for extension domains from Sobolev to

Tapio Rajala, Zheng Zhu

In this note, we prove that the boundary of a -extension domain is of volume zero under the assumption that the domain $\boz$ is -fat at almost every $x\in\parti…

math.AP2021

The extension property for domains with one singular point

Pekka Koskela, Zheng Zhu

An arbitrary outward cuspidal domain is shown to be bi-Lipschitz equivalent to a Lipschitz outward cuspidal domain via a global transformation. This allows us to extend earlier Sob…

math.FA2021

Bi-Lipschitz invariance of planar - and -extension domains

Miguel García-Bravo, Tapio Rajala, Zheng Zhu

We prove that a bi-Lipschitz image of a planar -extension domain is also a -extension domain, and that a bi-Lipschitz image of a planar -extension domain is again…

math.FA2021

Sobolev Extension on -Quasidisks

Zheng Zhu

In this paper, we study the Sobolev extension property of Lp-quasidisks which are the generalizations of the classical quasidisks. After that, we also find some applications of the…

math.FA2021

Pointwise inequalities for Sobolev functions on generalized cuspidal domains

Zheng Zhu

We establish point wise inequalities for Sobolev functions on a wider class of outward cuspidal domains. It is a generalization of an earlier result by the author and his collabora…

math.AP2020

The volume of the boundary of a Sobolev -extension domain

Pekka Koskela, Alexander Ukhlov, Zheng Zhu

Let and $1\leq q<p<\fz$. We prove that if is a Sobolev -extension domain, with additional capacitory restrictions on boundary in the case $q…

math.FA2019★ 2 cited

Pointwise inequalities for Sobolev functions on outward cuspidal domains

Sylvester Eriksson-Bique, Pekka Koskela, Jan Maly +1

We show that the first order Sobolev spaces on cuspidal symmetric domains can be characterized via pointwise inequalities. In particular, they coincide with the Hajlasz-Sobolev spa…

math.CA2019

Singularities In L p-quasidisks

Tadeusz Iwaniec, Jani Onninen, Zheng Zhu

We study planar domains with exemplary boundary singularities of the form of cusps. A natural question is how much elastic energy is needed to flatten these cusps; that is, to remo…

math.CA2019

Creating and Flattening Cusp Singularities by Deformations of Bi-conformal Energy

Tadeusz Iwaniec, Jani Onninen, Zheng Zhu

Mappingsofbi-conformalenergyformthewidestclass of homeomorphisms that one can hope to build a viable extension of Geometric Function Theory with connections to mathematical models…

math.CA2019★ 12 cited

Deformations of Bi-conformal Energy and a new Characterization of Quasiconformality

Tadeusz Iwaniec, Jani Onninen, Zheng Zhu

The concept of hyperelastic deformations of bi-conformal energy is developed as an extension of quasiconformality. These are homeomorphisms between domains $ X, Y \subs…

math.FA2018

Product of extension domains is still an extension domain

Pekka Koskela, Zheng Zhu

We prove the product of the Sobolev-extension domains is still a Sobolev-extension domain.