Results 31 to 40 of about 47 (46)

Subordination criteria for starlikeness and convexity

International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 32, Page 2053-2059, 2003., 2003
For functions p analytic in the open unit disc U = {z : |z| < 1} with the normalization p(0) = 1, we consider the families 𝒫[A, −1], −1 < A ≤ 1, consisting of p such that p(z) is subordinate to (1 + Az)/(1 − z) in U and 𝒫(1, b), b > 0, consisting of p, which have the disc formulation |p − 1| < b in U.
Rasoul Aghalary, Jay M. Jahangiri
wiley   +1 more source

Certain convex harmonic functions

International Journal of Mathematics and Mathematical Sciences, Volume 29, Issue 8, Page 459-465, 2002., 2002
We define and investigate a family of complex‐valued harmonic convex univalent functions related to uniformly convex analytic functions. We obtain coefficient bounds, extreme points, distortion theorems, convolution and convex combinations for this family.
Yong Chan Kim, Jay M. Jahangiri, Jae Ho Choi   +2 more
wiley   +1 more source

A subordination theorem for spirallike functions

International Journal of Mathematics and Mathematical Sciences, Volume 24, Issue 7, Page 433-435, 2000., 2000
We prove a subordination relation for a subclass of the class of λ‐spirallike functions.
Sukhjit Singh
wiley   +1 more source

On Logarithmic and Inverse Coefficients for Sakaguchi-Type Starlike Functions Subordinated to a Petal-Shaped Domain

Journal of Function Spaces
MSC2020 Classification: 30C45, 30C50 ...
Adel A. Attiya, Mohammad El-Ityan, Muhammad Abbas, Muntasir Suhail, Daniel Breaz   +4 more
doaj   +1 more source

Unified Approach of the Logarithmic Coefficient Bounds for the Class of Bazilevic˘ Functions

Journal of Function Spaces, Volume 2026, Issue 1, 2026.
The investigation of logarithmic coefficients in the theory of univalent functions began with Milin, who demonstrated their importance for understanding geometric features of these mappings through their connection with the Taylor coefficients hm. If S denotes the family of univalent functions on the unit disk D with the expansion hz=z+∑m=2∞hmzm, the ...
Ebrahim Analouei Adegani, Nafya Hameed Mohammed, Teodor Bulboacă, Giovanni Di Fratta   +3 more
wiley   +1 more source

A new criterion for close‐to‐convexity of partial sums of certain hypergeometric functions

International Journal of Stochastic Analysis, Volume 10, Issue 2, Page 197-202, 1997., 1997
We consider the partial sums of certain hypergeometric functions and establish conditions imposed on the locations of zeros of those polynomials in order to be close‐to‐convex in the open unit disk.
Massoud Jahangiri
wiley   +1 more source

Initial Coefficient Bounds of Convex Functions Related to Pascal Snail Function

Journal of Mathematics, Volume 2026, Issue 1, 2026.
For −1 ≤ λ ≤ 1, let Cλ be a subclass of convex functions associated with the Pascal snail function, analytically defined by the subordination relation, (1 + τf″(τ)/f′(τ))≺1/(1 − λτ). In this article, we have presented the initial coefficient bounds for the functions f in the class Cλ. We have also established the bounds on the Hankel determinants |H2,1(
Arooj Fatima, Umar Raza, Afis Saliu, Tanweer Sohail, Mohammad W. Alomari   +4 more
wiley   +1 more source

Univalence for convolutions

International Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 1, Page 201-203, 1996., 1996
The radius of univalence is found for the convolution f∗g of functions f ∈ S (normalized univalent functions) and g ∈ C (close‐to‐convex functions). A lower bound for the radius of univalence is also determined when f and g range over all of S. Finally, a characterization of C provides an inclusion relationship.
Herb Silverman
wiley   +1 more source

Hadamard Product on Subclasses of Meromorphic Functions Involving q‐Difference Operator

Journal of Function Spaces, Volume 2025, Issue 1, 2025.
By making use of a q‐derivative operator, certain families of meromorphic q‐starlike functions and meromorphic q‐convex functions are introduced and studied. In this paper, we define a q‐analogous value of differential operators for meromorphic functions with the help of basic concepts of quantum (q‐)calculus operator theory and introduce new ...
W. Y. Kota, R. M. El-Ashwah, Nicoleta Breaz, Shrideh K. Q. Al-Omari   +3 more
wiley   +1 more source

A class of bounded starlike functions

International Journal of Mathematics and Mathematical Sciences, Volume 17, Issue 2, Page 249-252, 1994., 1994
We consider functions f(z) = z + … that are analytic in the unit disk and satisfy there the inequality Re(f′(z) + zf″(z)) > α, α < 1. We find extreme points and then determine sharp lower bounds on Ref′(z) and Re(f(z)/z). Sharp results for the sequence of partial sums are also found.
Herb Silverman
wiley   +1 more source