TY - JOUR T1 - The Distortion Theorems for Harmonic Mappings with Negative Coefficient Analytic Parts AU - Zhu , Mengkun AU - Huang , Xinzhong JO - Journal of Mathematical Study VL - 1 SP - 23 EP - 32 PY - 2016 DA - 2016/03 SN - 49 DO - http://doi.org/10.4208/jms.v49n1.16.03 UR - https://global-sci.org/intro/article_detail/jms/985.html KW - Harmonic mapping, coefficient estimate, distortion theorem, covering problem. AB -
Some sharp estimates for coefficients, distortion and the growth order are obtained for harmonic mappings $f \in TL^{\alpha}_H,$ which are locally univalent harmonic mappings in the unit disk $\mathbb{D}:=\{z:|z|<1\}.$ Moreover, denoting the subclass $TS^{\alpha}_H$ of the normalized univalent harmonic mappings, we also estimate the growth of $|f|,$ $f \in TS^α_H,$ and their covering theorems.