On the heterogeneous distortion inequality
arXiv:2102.03471 · doi:10.1007/s00208-021-02315-2
Abstract
We study Sobolev mappings , , that satisfy the heterogeneous distortion inequality \[\left|Df(x)\right|^n \leq K J_f(x) + σ^n(x) \left|f(x)\right|^n\] for almost every . Here is a constant and is a function in . Although we recover the class of -quasiregular mappings when , the theory of arbitrary solutions is significantly more complicated, partly due to the unavailability of a robust degree theory for non-quasiregular solutions. Nonetheless, we obtain a Liouville-type theorem and the sharp Hölder continuity estimate for all solutions, provided that for some . This gives an affirmative answer to a question of Astala, Iwaniec and Martin.