A1 Refereed original research article in a scientific journal

On quasi-inversions




AuthorsKalaj D, Vuorinen M, Wang GD

PublisherSPRINGER WIEN

Publication year2016

JournalMonatshefte für Mathematik

Journal name in sourceMONATSHEFTE FUR MATHEMATIK

Journal acronymMONATSH MATH

Volume180

Issue4

First page 785

Last page813

Number of pages29

ISSN0026-9255

DOIhttps://doi.org/10.1007/s00605-016-0919-8


Abstract
Given a bounded domain strictly starlike with respect to we define a quasi-inversion w.r.t. the boundary We show that the quasi-inversion is bi-Lipschitz w.r.t. the chordal metric if and only if every "tangent line" of is far away from the origin. Moreover, the bi-Lipschitz constant tends to 1, when approaches the unit sphere in a suitable way. For the formulation of our results we use the concept of the -tangent condition due to Gehring and Vaisala (Acta Math 114:1-70,1965). This condition is shown to be equivalent to the bi-Lipschitz and quasiconformal extension property of what we call the polar parametrization of . In addition, we show that the polar parametrization, which is a mapping of the unit sphere onto , is bi-Lipschitz if and only if D satisfies the -tangent condition.



Last updated on 2024-26-11 at 23:22