English

Sobolev homeomorphic extensions

Complex Variables 2018-12-06 v1

Abstract

Let X\mathbb X and Y\mathbb Y be \ell-connected Jordan domains, N\ell \in \mathbb N, with rectifiable boundaries in the complex plane. We prove that any boundary homeomorphism φ ⁣:XY\varphi \colon \partial \mathbb X \to \partial \mathbb Y admits a Sobolev homeomorphic extension h ⁣:XYh \colon \overline{\mathbb X} \to \overline{\mathbb Y} in W1,1(X,C)W^{1,1} (\mathbb X, \mathbb C). If instead X\mathbb X has ss-hyperbolic growth with s>p1s>p-1, we show the existence of such an extension lies in the Sobolev class W1,p(X,C)W^{1,p} (\mathbb X, \mathbb C) for p(1,2)p\in (1,2). Our examples show that the assumptions of rectifiable boundary and hyperbolic growth cannot be relaxed. We also consider the existence of W1,2W^{1,2}-homeomorphic extensions subject to a given boundary data.

Keywords

Cite

@article{arxiv.1812.02085,
  title  = {Sobolev homeomorphic extensions},
  author = {Aleksis Koski and Jani Onninen},
  journal= {arXiv preprint arXiv:1812.02085},
  year   = {2018}
}

Comments

25 pages, 5 figures

R2 v1 2026-06-23T06:32:54.944Z