Coefficient bounds for a generalized subclass of bounded turning functions associated with Sigmoid function

In this paper, we introduce a subclass of analytic functions associated with the Sigmoid function and determine the upper bounds for various coefficient functionals such as  Fekete-Szego functional, second Hankel determinant, Zalcman functional and third Hankel determinant. Also, the concept is extended to two-fold and three-fold symmetric functions. The results proved earlier, follow as special cases of the results of this paper.

کلیدواژه ها:

subordination ، Hankel determinant ، Fekete Szego functional ، Zalcman functional