Semigroup-fication of univalent self-maps of the unit disc
Abstract
Let be a univalent self-map of the unit disc. We introduce a technique, that we call {\sl semigroup-fication}, which allows to construct a continuous semigroup of holomorphic self-maps of the unit disc whose time one map is, in a sense, very close to . The semigrup-fication of is of the same type as (elliptic, hyperbolic, parabolic of positive step or parabolic of zero step) and there is a one-to-one correspondence between the set of boundary regular fixed points of with a given multiplier and the corresponding set for . Moreover, in case (and hence ) has no interior fixed points, the slope of the orbits converging to the Denjoy-Wolff point is the same. The construction is based on holomorphic models, localization techniques and Gromov hyperbolicity. As an application of this construction, we prove that in the non-elliptic case, the orbits of converge non-tangentially to the Denjoy-Wolff point if and only if the Koenigs domain of is "almost symmetric" with respect to vertical lines.
Keywords
Cite
@article{arxiv.2002.08252,
title = {Semigroup-fication of univalent self-maps of the unit disc},
author = {Filippo Bracci and Oliver Roth},
journal= {arXiv preprint arXiv:2002.08252},
year = {2020}
}