2000 Mathematics Subject Classification: Primary 30C45, secondary 30C80.We consider some familiar subclasses of functions starlike with respect to symmetric points and obtain sufficient conditions for these classes in terms of their Taylor coefficient. This leads to obtain several new examples of these subclasses.
Let D = z: Re z < 0 and let S*(D) be the class of univalent functions normalized by the conditions , a a finite complex number, 0 ∉ f(D), and mapping D onto a domain f(D) starlike with respect to the exterior point w = 0. Some estimates for |f(z)| in the class S*(D) are derived. An integral formula for f is also given.
In this paper we discuss some subordination results for a subclass of functions analytic in the unit disk U
In this paper, we obtain new sufficient conditions for the operators Fα1,α2,…,αn,β(z) and Gα1,α2,…,αn,β(z) to be univalent in the open unit disc U, where the functions f1, f2, …, fn belong to the classes S*(a, b) and K(a, b). The order of convexity for the operators Fα1,α2,…,αn,β(z) and Gα1,α2,…,αn,β(z) is also determined. Furthermore, and for β = 1, we obtain sufficient conditions for the operators Fn(z) and Gn(z) to be in the class K(a, b). Several corollaries and consequences of the main results...
We geometrically define subclasses of starlike functions related to the class of uniformly starlike functions introduced by A. W. Goodman in 1991. We give an analytic characterization of these classes, some radius properties, and examples of functions in these classes. Our classes generalize the class of uniformly starlike functions, and many results of Goodman are special cases of our results.