Quantitative Sobolev regularity of quasiregular maps

We quantify the Sobolev space norm of the Beltrami resolvent $(I- μ\mathcal{B})^{-1}$, where $\mathcal B$ is the Beurling-Ahlfors transform, in terms of the corresponding Sobolev space norm of the dilatation $μ$ in the critical and supercritical ranges. Our estimate entails as a consequence quantitative self-improvement inequalities of Caccioppoli type for quasiregular distributions with dilatations in $W^{1,p}$, $p \geq 2$. Our proof strategy is then adapted to yield quantitative estimates for ...