English

Quasiconformal extensions, Loewner chains, and the lambda-Lemma

Complex Variables 2020-06-09 v1

Abstract

In 1972, J. Becker [J. Reine Angew. Math. 255] discovered a sufficient condition for quasiconformal extendibility of Loewner chains. Many known conditions for quasiconformal extendibility of holomorphic functions in the unit disk can be deduced from his result. We give a new proof of (a generalization of) Becker's result based on Slodkowski's Extended lambda-Lemma. Moreover, we characterize all quasiconformal extensions produced by Becker's (classical) construction and use that to obtain examples in which Becker's extension is extremal (i.e. optimal in the sense of maximal dilatation) or, on the contrary, fails to be extremal.

Keywords

Cite

@article{arxiv.1712.08632,
  title  = {Quasiconformal extensions, Loewner chains, and the lambda-Lemma},
  author = {Pavel Gumenyuk and István Prause},
  journal= {arXiv preprint arXiv:1712.08632},
  year   = {2020}
}
R2 v1 2026-06-22T23:27:47.825Z