Coecient Estimates for Three Generalized Classes of Meromorphic and Bi- Univalent Functions

Abstract

In this paper, we introduce and investigate three
interesting subclass $\Sigma_\vartheta^*(\lambda,\alpha)$, $\Sigma_\vartheta^B(\beta,\alpha)$ and $\tilde{\Sigma}_\vartheta^*(\alpha,\beta)$ of meromorphic and
bi-univalent functions on $\Delta=\{z\in\mathbb{C}: |z|>1\}$, obtain their coefficient
estimates. The results presented in this paper generalize the recent work S.A.Halim et al.[1].