The Sobolev Jordan-Schonflies Problem

Abstract

We consider the planar unit disk $\mathbb{D}$ as the reference configuration and a Jordan domain $\mathbb{Y}$ as the deformed configuration, and study the problem of extending a given boundary homeomorphism $\phi :\partial \mathbb{D}\to \partial \mathbb{Y}$ as a Sobolev homeomorphism of the complex plane. Investigating such a Sobolev variant of the classical Jordan-Schönflies theorem is motivated by the well-posedness of the related pure displacement variational questions in the theory of Nonlinear Elasticity (NE) and Geometric Function Theory (GFT). Clearly, the necessary condition for the boundary mapping $\phi$ to admit a $W^{1,p}$-Sobolev homeomorphic extension is that it first admits a continuous $W^{1,p}$-Sobolev extension. For an arbitrary target domain $\mathbb{Y}$ this, however, is not sufficent.

32 pages, 13 figures