Аннотация:
In 1963, Ahlfors posed in [1] (and repeated in his book [2]) the
following question which gave rise to various investigations of quasiconformal extendibility of univalent functions.
Question.Let $f$ be a conformal map of the
disk (or half-plane) onto a domain with quasiconformal boundary
(quasicircle). How can this map be characterized? He conjectured that the characterization should be in analytic
properties of the logarithmic derivative $\log f^\prime =
f^{\prime\prime}/f^\prime$, and indeed, many results on quasiconformal extensions of holomorphic maps have been established using
$f^{\prime\prime}/f^\prime$ and other invariants (see, e.g., the
survey [9] and the references there).
This question relates to another still not solved problem in
geometric complex analysis:
To what extent does the Riemann mapping function $f$ of a
Jordan domain$D \subset \hat {\Bbb C}$determine the geometric and conformal
invariants (characteristics) of complementary domain$D^* = \hat {\Bbb C}
\setminus \overline{D}$?
The purpose of this paper is to provide a qualitative answer to
these questions, which discovers how the inner features of
biholomorphy determine the admissible bounds for quasiconformal dilatations
and determine the Kobayashi distance for the corresponding points in the
universal Teichmüller space.