Published online by Cambridge University Press: 07 August 2017
The family ${\mathcal{F}}_{\unicode[STIX]{x1D706}}$ of orientation-preserving harmonic functions $f=h+\overline{g}$ in the unit disc $\mathbb{D}$ (normalised in the standard way) satisfying
The second and third authors are supported by Fondecyt, Chile, grant 1150284. The third author is also partially supported by grant MTM2015-65792-P from MINECO/FEDER, the Thematic Research Network MTM2015-69323-REDT, MINECO, Spain, and the Academy of Finland, grant 268009.