# Seminario: “Strengthened extremal bounds for moduli of annuli under distortions by univalent and multivalent functions”

## Lunedì 17 Settembre 2018, ore 12:00 - Aula 2AB40 - Anatoly Golberg

ARGOMENTI: Seminari

Lunedì 17 Settembre 2018 alle ore 12:00 in Aula 2AB40, Anatoly Golberg (Holon Institute of Technology, Israel) terrà un seminario dal titolo: “Strengthened extremal bounds for moduli of annuli under distortions by univalent and multivalent functions”.
Abstract
The theorems of TWB (Teichmueller-Wittich-Belinskiii) type imply the local conformality in the strong or weakened sense generating deep features of quasiconformal mappings at a prescribed point under assumptions of the finiteness of appropriate integral averages of the quantity $K_f(z) - 1;$ where $K_f(z)$ stands for the real dilatation coefficient.
In the talk, we present the strengthened extremal bounds for distortions of the moduli of annuli in terms of integrals in TWB theorems under quasiconformal and quasiregular mappings and illustrate their sharpness by different examples. Several local conditions weaker than the conformality are also discussed.