scholarly journals MEROMORPHIC UNIVALENT FUNCTIONS WITH NEGATIVE COEFFICIENTS

1996 ◽  
Vol 27 (1) ◽  
pp. 81-88
Author(s):  
S. M. SARANGI ◽  
SUGUNA B. URALEGADDI

Coefficient inequalities, distortion theorem, extreme points and prop­ erty preserving integral operators are obtained for certam subclasses of meromor­phic starlike functions with negative coefficints. Convolutions of functions in these classes are also obtained.

2020 ◽  
Vol 16 (2) ◽  
pp. 39-49
Author(s):  
P. Thirupathi Reddy ◽  
B. Venkateswarlu ◽  
S. Sreelakshmi

AbstractIn this paper, we introduce and study a new class σ, (α,λ) of meromorphic univalent functions defined in E = {z : z ∊ ℂ and 0 < |z| < 1} = E \ {0}. We obtain coefficient inequalities, distortion theorems, extreme points, closure theorems, radius of convexity estimates and integral operators. Finally, we obtained neighbourhood result for the class σp(γ,λ).


2021 ◽  
Vol 21 (1) ◽  
pp. 26-38
Author(s):  
B. Venkateswarlu ◽  
◽  
P Thirupathi Reddy ◽  
R. Madhuri Shilpa ◽  
Sujatha ◽  
...  

In this paper, we introduce and study a new subclass of meromorphic univalent functions defined by Hurwitz-Lerch Zeta function. We obtain coefficient inequalities, extreme points, radius of starlikeness and convexity. Finally we obtain partial sums and neighborhood properties for the class $\sigma^*(\gamma, k, \lambda, b, s).$


1985 ◽  
Vol 32 (2) ◽  
pp. 161-176 ◽  
Author(s):  
M.L. Mogra ◽  
T.R. Reddy ◽  
O.P. Juneja

For the class of meromorphically starlike functions of prescribed order, the concept of type has been introduced. A characterization of meromorphically starlike functions of order α and type β has been obtained when the coefficients in its Laurent series expansion about the origin are all positive. This leads to a study of coefficient estimates, distortion theorems, radius of convexity estimates, integral operators, convolution properties et cetera for this class. It is seen that the class considered demonstrates, in some respects, properties analogous to those possessed by the corresponding class of univalent analytic functions with negative coefficients.


2014 ◽  
Vol 45 (2) ◽  
pp. 149-163
Author(s):  
Bakr Hussein Rizqan ◽  
H.E. Darwish ◽  
A.Y. Lashin

A certain subclass Bm(p,α,λ,ℓ,A,B) consisting of meromorphic p-valent functions with alternating coefficient in U∗={z:z∈C:0<|z|<1} is introduced. In this paper we obtain coefficient inequalities, distortion theorem, closure theorems and class preserving integral operators for functions in the class Bm(p,α,λ,ℓ,A,B) are obtained .


Author(s):  
Deepali Khurana ◽  
Raj Kumar ◽  
Sibel Yalcin

We define two new subclasses, $HS(k, \lambda, b, \alpha)$ and \linebreak $\overline{HS}(k, \lambda, b, \alpha)$, of univalent harmonic mappings using multiplier transformation. We obtain a sufficient condition for harmonic univalent functions to be in $HS(k,\lambda,b,\alpha)$ and we prove that this condition is also necessary for the functions in the class $\overline{HS} (k,\lambda,b,\alpha)$. We also obtain extreme points, distortion bounds, convex combination, radius of convexity and Bernandi-Libera-Livingston integral for the functions in the class $\overline{HS}(k,\lambda,b,\alpha)$.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Saqib Hussain ◽  
Akhter Rasheed ◽  
Muhammad Asad Zaighum ◽  
Maslina Darus

We investigate some subclasses ofk-uniformly convex andk-uniformly starlike functions in open unit disc, which is generalization of class of convex and starlike functions. Some coefficient inequalities, a distortion theorem, the radii of close-to-convexity, and starlikeness and convexity for these classes of functions are studied. The behavior of these classes under a certain modified convolution operator is also discussed.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
A. Y. Lashin

Coefficient conditions, distortion bounds, extreme points, convolution, convex combinations, and neighborhoods for a new class of harmonic univalent functions in the open unit disc are investigated. Further, a class preserving integral operator and connections with various previously known results are briefly discussed.


Author(s):  
O. P. Ahuja

A functionf, analytic in the unit discΔ, is said to be in the familyRn(α)ifRe{(znf(z))(n+1)/(zn−1f(z))(n)}>(n+α)/(n+1)for someα(0≤α<1)and for allzinΔ, wheren ϵ No,No={0,1,2,…}. The The classRn(α)contains the starlike functions of orderαforn≥0and the convex functions of orderαforn≥1. We study a class of integral operators defined onRn(α). Finally an argument theorem is proved.


2010 ◽  
Vol 60 (1) ◽  
Author(s):  
Waggas Atshan

AbstractIn this paper, we introduce a new class W(a, b, c, γ, β) which consists of analytic and univalent functions with negative coefficients in the unit disc defined by Hohlov operator, we obtain distortion theorem using fractional calculus techniques for this class. Also coefficient inequalities and some results for this class are obtained.


2012 ◽  
Vol 2012 ◽  
pp. 1-11
Author(s):  
N. Magesh ◽  
N. B. Gatti ◽  
S. Mayilvaganan

We introduce and study a subclass ΣP(γ,k,λ,c) of meromorphic univalent functions defined by certain linear operator involving the generalized hypergeometric function. We obtain coefficient estimates, extreme points, growth and distortion inequalities, radii of meromorphic starlikeness, and convexity for the class ΣP(γ,k,λ,c) by fixing the second coefficient. Further, it is shown that the class ΣP(γ,k,λ) is closed under convex linear combination.


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