Haiqing Xu

activity

20162021

collaborators

8 papers

math.CV2021

Improved regularity of harmonic diffeomorphic extensions on quasihyperbolic domains

Zhuang Wang, Haiqing Xu

Let $X$ be a Jordan domain satisfying hyperbolic growth conditions. Assume that $φ$ is a homeomorphism from the boundary $\partial X$ of $X$ onto the uni…

math.CV2020

Generalized quasidisks and conformality: progress and challenges

Chang-Yu Guo, Haiqing Xu

In this notes, we survey the recent developments on theory of generalized quasidisks. Based on the more or less standard techniques used earlier, we also provide some minor improve…

math.CV2019

Optimal extensions of conformal mappings from the unit disk to cardioid-type domains

Haiqing Xu

The conformal mapping $f (z) = (z + 1)^{2}$ from $D$ onto the standard cardioid has a homeomorphic extension of finite distortion to entire $R^{2} .$ We study the optimal…

math.CV2019

Weighted estimates for diffeomorphic extensions of homeomorphisms

Haiqing Xu

Let $Ω\subset \mbr^2$ be an internal chord-arc domain and $φ: \mbs^1 \rightarrow \partial Ω$ be a homeomorphism. Then there is a diffeomorphic extension $h : \mbd \rightarrow Ω$ of…

math.CV2018

Controlled diffeomorphic extension of homeomorphisms

Pekka Koskela, Zhuang Wang, Haiqing Xu

Let $Ω$ be an internal chord-arc Jordan domain and $φ : S \to \partial Ω$ be a homeomorphism. We show that $φ$ has finite dyadic energy if and only if $φ$ has a diffeomo…

stat.ME2018

Estimation of treatment effects under endogeneous heteroskedasticity

Jason Abrevaya, Haiqing Xu

The empirical literature on program evaluation limits its scope almost exclusively to models where treatment effects are homogenous for observationally identical individuals. This…