BV and Sobolev homeomorphisms between metric measure spaces and the plane

Abstract

We show that given a homeomorphism $f:G\rightarrow\Omega$ where $G$ is a open subset of $\mathbb{R}^2$ and $\Omega$ is a open subset of a $2$-Ahlfors regular metric measure space supporting a weak $(1,1)$-Poincar\'e inequality, it holds $f\in BV_{\operatorname{loc}}(G,\Omega)$ if and only $f^{-1}\in BV_{\operatorname{loc}}(\Omega,G)$. Further if $f$ satisfies the Luzin N and N$^{-1}$ conditions then $f\in W^{1,1}_{\operatorname{loc}}(G,\Omega)$ if and only if $f^{-1}\in W^{1,1}_{\operatorname{loc}}(\Omega,G)$.