Publishing house / Banach Center Publications / All volumes

Abstract

Quasihomography is a useful notion to represent a sense-preserving automorphism of the unit circle T which admits a quasiconformal extension to the unit disc. For K ≥ 1 let $A_T(K)$ denote the family of all K-quasihomographies of T. With any $f ∈ A_T(K)$ we associate the Douady-Earle extension $E_f$ and give an explicit and asymptotically sharp estimate of the $L_∞$ norm of the complex dilatation of $E_f$.