Quasi-subordination and coefficient bounds for certain classes of meromorphic functions of complex order

Abstract

In this paper, we obtain Fekete-Szegö functional |a₁-μa₀²| for functions of the classes Σ_{q}^{∗}(ϕ) and Σ_{q,λ,b}^{∗}(g,ϕ) using quasi-subordination. Sharp bounds for the Fekete-Szegö functional |a₁-μa₀²| are obtained. Also, applications of the main results for subclasses of functions defined by Bessel function are also considered.