Yi-Ru-Ya Zhang

activity

20162026

most citedA quasiconformal composition problem for the Q-spaces

1 citations · 1 across the 13 of their papers we have counts for

collaborators

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3 papers · 1 filter

math.FA2025

Planar $W^{1, 1}$ -extension domains

Pekka Koskela, Tapio Rajala, Yi Ru-Ya Zhang

We show that a bounded planar simply connected domain $Ω$ is a $W^{1, 1}$ -extension domain if and only if for every pair $x, y$ of points in $Ω^{c}$ there exists a curve $γ\subset Ω^…

math.FA2020

Sharp gradient stability for the Sobolev inequality

Alessio Figalli, Yi Ru-Ya Zhang

We prove a sharp quantitative version of the $p$ -Sobolev inequality for any $1 < p < n$ , with a control on the strongest possible distance from the class of optimal functions. Surprisi…

math.FA2016★ 1 cited

A quasiconformal composition problem for the Q-spaces

Pekka Koskela, Jie Xiao, Yi Ru-Ya Zhang +1

Given a quasiconformal mapping $f : R^{n} \to R^{n}$ with $n \geq 2$ , we show that (un-)boundedness of the composition operator $C_{f}$ on the spaces $Q_{α} (R^{n})$ de…

Planar W1,1-extension domains

Sharp gradient stability for the Sobolev inequality

A quasiconformal composition problem for the Q-spaces

Planar $W^{1, 1}$ -extension domains