scholarly journals Coefficient Bounds for Some Families of Starlike and Convex Functions of Reciprocal Order

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Muhammad Arif ◽  
Maslina Darus ◽  
Mohsan Raza ◽  
Qaiser Khan

The aim of the present paper is to investigate coefficient estimates, Fekete-Szegő inequality, and upper bound of third Hankel determinant for some families of starlike and convex functions of reciprocal order.

2014 ◽  
Vol 07 (02) ◽  
pp. 1350042
Author(s):  
D. Vamshee Krishna ◽  
T. Ramreddy

The objective of this paper is to obtain an upper bound to the second Hankel determinant [Formula: see text] for the functions belonging to strongly starlike and convex functions of order α(0 < α ≤ 1). Further, we introduce a subclass of analytic functions and obtain the same coefficient inequality for the functions in this class, using Toeplitz determinants.


Filomat ◽  
2017 ◽  
Vol 31 (11) ◽  
pp. 3307-3318
Author(s):  
Nirupam Ghosh ◽  
A. Vasudevarao

In this article we determine the coefficient bounds for functions in certain subclasses of analytic functions defined by subordination which are related to the well-known classes of starlike and convex functions. The main results deal with some open problems proposed by Q.H. Xu et al.([20], [21]). An application of Jack lemma for certain subclass of starlike functions has been discussed.


Author(s):  
D. Vamshee Krishna ◽  
B. Venkateswarlu ◽  
T. RamReddy

The objective of this paper is to obtain best possible upper bound to the \(H_{3}(1)\)  Hankel determinant for starlike and convex functions with respect to symmetric points, using Toeplitz determinants.


2007 ◽  
Vol 20 (12) ◽  
pp. 1218-1222 ◽  
Author(s):  
Osman Altıntaş ◽  
Hüseyin Irmak ◽  
Shigeyoshi Owa ◽  
H.M. Srivastava

2017 ◽  
Vol 95 (3) ◽  
pp. 446-456 ◽  
Author(s):  
SARITA AGRAWAL

For every $q\in (0,1)$, we obtain the Herglotz representation theorem and discuss the Bieberbach problem for the class of $q$-convex functions of order $\unicode[STIX]{x1D6FC}$ with $0\leq \unicode[STIX]{x1D6FC}<1$. In addition, we consider the Fekete–Szegö problem and the Hankel determinant problem for the class of $q$-starlike functions, leading to two conjectures for the class of $q$-starlike functions of order $\unicode[STIX]{x1D6FC}$ with $0\leq \unicode[STIX]{x1D6FC}<1$.


Author(s):  
P. Gochhayat ◽  
A. Prajapati ◽  
A. K. Sahoo

A typical quandary in geometric functions theory is to study a functional composed of amalgamations of the coefficients of the pristine function. Conventionally, there is a parameter over which the extremal value of the functional is needed. The present paper deals with consequential functional of this type. By making use of Hohlov operator, a new subclass [Formula: see text] of analytic functions defined in the open unit disk is introduced. For both real and complex parameter, the sharp bounds for the Fekete–Szegö problems are found. An attempt has also been taken to found the sharp upper bound to the second and third Hankel determinant for functions belonging to this class. All the extremal functions are express in term of Gauss hypergeometric function and convolution. Finally, the sufficient condition for functions to be in [Formula: see text] is derived. Relevant connections of the new results with well-known ones are pointed out.


2018 ◽  
Vol 68 (1) ◽  
pp. 89-102
Author(s):  
C. Ramachandran ◽  
R. Ambrose Prabhu ◽  
Srikandan Sivasubramanian

AbstractEnough attentions to domains related to conical sections has not been done so far although it deserves more. Making use of the conical domain the authors have defined a new class of starlike and Convex Functions with respect to symmetric points involving the conical domain. Growth and distortion estimates are studied with convolution using domains bounded by conic regions. Certain coefficient estimates are obtained for domains bounded by conical region. Finally interesting application of the results are also highlighted for the function Ωk,βdefined by Noor.


2012 ◽  
Vol 25 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Rosihan M. Ali ◽  
See Keong Lee ◽  
V. Ravichandran ◽  
Shamani Supramaniam

Geometry ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Gagandeep Singh ◽  
B. S. Mehrok

The objective of the present paper is to obtain the sharp upper bound of for p-valent α-convex functions of the form in the unit disc .


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