Second Hankel Determinant of Logarithmic Coefficients of Convex and Starlike Functions of Order Alpha

In the present paper, we found sharp bounds of the second Hankel determinant of logarithmic coefficients of starlike and convex functions of order $$\alpha $$ α .

Hankel determinants for starlike and convex functions associated with sigmoid functions

This paper is concerned with Hankel determinants for starlike and convex functions related to modified sigmoid functions. Sharp bounds are given for second and third Hankel determinants.

Radius Problems for Starlike Functions Associated with the Tan Hyperbolic Function

The aim of this particular article is at studying a holomorphic function f defined on the open-unit disc D = z ∈ ℂ : z < 1 for which the below subordination relation holds z f ′ z / f z ≺ q 0 z = 1 + tan h z . The class of such functions is denoted by S tan h ∗ . The radius constants of such functions are estimated to conform to the classes of starlike and convex functions of order β and Janowski starlike functions, as well as the classes of starlike functions associated with some familiar functions.

Study on new integral operators defined using confluent hypergeometric function

Two new integral operators are defined in this paper using the classical Bernardi and Libera integral operators and the confluent (or Kummer) hypergeometric function. It is proved that the new operators preserve certain classes of univalent functions, such as classes of starlike and convex functions, and that they extend starlikeness of order $\frac{1}{2}$ 1 2 and convexity of order $\frac{1}{2}$ 1 2 to starlikeness and convexity, respectively. For obtaining the original results, the method of admissible functions is used, and the results are also written as differential inequalities and interpreted using inclusion properties for certain subsets of the complex plane. The example provided shows an application of the original results.

Starlikeness and convexity of the product of certain multivalent functions with higher-order derivatives

In this paper we introduce some new subclasses of the p-valent analytic functions with higher-order derivatives that generalize some related subclasses of starlike and convex functions of a positive order. We found the order of (p,q)-valent starlikeness and convexity for the products of functions that belong to these classes. The order of (p,q)-valent starlikeness and convexity of certain integral operators for the product of functions of these classes were also obtained.

Some new classes of analytic functions related to shell-like curve associated with ruscheweyh q-differential operator

In this paper, we study some new results such as coefficients bounds and Fekete–Szegö inequalities of the certain classes starlike and convex functions associated with shell-like defined using the concept of Ruscheweyh [Formula: see text]-differential operator. Comparisons of new results with those that were obtained in earlier investigation are given as corollaries.