Mapping Theorems

Abstract

Ahlfors and Gehring asked for the Riemann Mapping Theorem for quasiconformal mappings (QC) of R^3. We summarise our solution: (a) QC reflections are tame (b) T is the fixed set of a QC reflection iff T is a uniform sphere (i.e. the limits of its blowups are topologically flat spheres) (c) T is a quasiphere iff is a uniform & quasisymmetric sphere (d) A domain D is the QC image of the unit ball iff it is a regular ball: uniformly simply connected (i.e. the limits of blowups are topological balls) with boundary mapping from the unit sphere which is regular (i.e. the limits of blowups are boundary maps from the sphere). The latter is equivalent to being locally linearly connected and Lowner.