Sobolev homeomorphic extensions

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