Mathematics, Vol. 11, Pages 2490: Norm Estimates of the Pre-Schwarzian Derivatives for Functions with Conic-like Domains

Mathematics, Vol. 11, Pages 2490: Norm Estimates of the Pre-Schwarzian Derivatives for Functions with Conic-like Domains

Mathematics doi: 10.3390/math11112490

Authors: Sidra Zafar Abbas Kareem Wanas Mohamed Abdalla Syed Zakar Hussain Bukhari

The pre-Schwarzianand Schwarzian derivatives of analytic functions f are defined in U, where U is the open unit disk. The pre-Schwarzian as well as Schwarzian derivatives are popular tools for studying the geometric properties of analytic mappings. These can also be used to obtain either necessary or sufficient conditions for the univalence of a function f. Because of the computational difficulty, the pre-Schwarzian norm has received more attention than the Schwarzian norm. It has applications in the theory of hypergeometric functions, conformal mappings, Teichmüller spaces, and univalent functions. In this paper, we find sharp norm estimates of the pre-Schwarzian derivatives of certain subfamilies of analytic functions involving some conic-like image domains. These results may also be extended to the families of strongly starlike, convex, as well as to functions with symmetric and conjugate symmetric points.