scholarly journals Certain q-difference operators and their applications to the subclass of meromorphic q-starlike functions

Filomat ◽  
2019 ◽  
Vol 33 (11) ◽  
pp. 3385-3397 ◽  
Author(s):  
Qazi Ahmad ◽  
Nazar Khan ◽  
Mohsan Raza ◽  
Muhammad Tahir ◽  
Bilal Khan
Keyword(s):  
Differential Operator ◽  
Meromorphic Functions ◽  
Difference Operator ◽  
Starlike Functions ◽  
Difference Operators ◽  
Sufficient Condition ◽  
Coefficient Inequalities ◽  
Meromorphic Starlike Functions

The main aim of this work is to find some coefficient inequalities and sufficient condition for some subclasses of meromorphic starlike functions by using q-difference operator. Here we also define the extended Ruscheweyh differential operator for meromorphic functions by using q-difference operator. Several properties such as coefficient inequalities and Fekete-Szego functional of a family of functions are investigated.

scholarly journals Coefficient Inequalities of a Subclass of Starlike Functions Involving q - Differential Operator

2018 ◽  
Vol 3 (2) ◽  
pp. 73-81 ◽  
Author(s):  
K. R. Karthikeyan ◽  
◽  
K. Amarender Reddy ◽  
M. Thirucheran ◽  
◽  
...  
Keyword(s):  
Differential Operator ◽  
Starlike Functions ◽  
Coefficient Inequalities

scholarly journals Higher-order q-derivatives and their applications to subclasses of multivalent Janowski type q-starlike functions

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Bilal Khan ◽  
Zhi-Guo Liu ◽  
H. M. Srivastava ◽  
Serkan Araci ◽  
Nazar Khan ◽  
...  
Keyword(s):  
Starlike Functions ◽  
Higher Order ◽  
Sufficient Condition ◽  
Function Classes ◽  
Janowski Functions ◽  
Radius Problems ◽  
Coefficient Inequalities

AbstractIn the present investigation, with the help of certain higher-order q-derivatives, some new subclasses of multivalent q-starlike functions which are associated with the Janowski functions are defined. Then, certain interesting results, for example, radius problems and the results related to distortion, are derived. We also derive a sufficient condition and certain coefficient inequalities for our defined function classes. Some known consequences related to this subject are also highlighted. Finally, the well-demonstrated fact about the $(p,q)$ ( p , q ) -variations is also given in the concluding section.

scholarly journals A Study of Some Families of Multivalent q-Starlike Functions Involving Higher-Order q-Derivatives

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1470
Author(s):  
Bilal Khan ◽  
Zhi-Guo Liu ◽  
Hari M. Srivastava ◽  
Nazar Khan ◽  
Maslina Darus ◽  
...  
Keyword(s):  
Starlike Functions ◽  
Higher Order ◽  
Open Unit ◽  
Sufficient Condition ◽  
Open Unit Disk ◽  
Function Classes ◽  
The Family ◽  
Radius Problems ◽  
Coefficient Inequalities ◽  
Distortion Theorems

In the present investigation, by using certain higher-order q-derivatives, the authors introduce and investigate several new subclasses of the family of multivalent q-starlike functions in the open unit disk. For each of these newly-defined function classes, several interesting properties and characteristics are systematically derived. These properties and characteristics include (for example) distortion theorems and radius problems. A number of coefficient inequalities and a sufficient condition for functions belonging to the subclasses studied here are also discussed. Relevant connections of the various results presented in this investigation with those in earlier works on this subject are also pointed out.

scholarly journals Bounds for the Coefficient of Faber Polynomial of Meromorphic Starlike and Convex Functions

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1368
Author(s):  
Oh Sang Kwon ◽  
Shahid Khan ◽  
Young Jae Sim ◽  
Saqib Hussain
Keyword(s):  
Real Axis ◽  
Convex Functions ◽  
Meromorphic Functions ◽  
Starlike Functions ◽  
Monic Polynomial ◽  
Faber Polynomial ◽  
Strongly Convex ◽  
Starlike And Convex Functions ◽  
Strongly Starlike ◽  
Meromorphic Starlike Functions

Let Σ be the class of meromorphic functions f of the form f ( ζ ) = ζ + ∑ n = 0 ∞ a n ζ − n which are analytic in Δ : = { ζ ∈ C : | ζ | > 1 } . For n ∈ N 0 : = N ∪ { 0 } , the nth Faber polynomial Φ n ( w ) of f ∈ Σ is a monic polynomial of degree n that is generated by a function ζ f ′ ( ζ ) / ( f ( ζ ) − w ) . For given f ∈ Σ , by F n , i ( f ) , we denote the ith coefficient of Φ n ( w ) . For given 0 ≤ α < 1 and 0 < β ≤ 1 , let us consider domains H α and S β ⊂ C defined by H α = { w ∈ C : Re ( w ) > α } and S β = { w ∈ C : | arg ( w ) | < β } , which are symmetric with respect to the real axis. A function f ∈ Σ is called meromorphic starlike of order α if ζ f ′ ( ζ ) / f ( ζ ) ∈ H α for all ζ ∈ Δ . Another function f ∈ Σ is called meromorphic strongly starlike of order β if ζ f ′ ( ζ ) / f ( ζ ) ∈ S β for all ζ ∈ Δ . In this paper we investigate the sharp bounds of F n , n − i ( f ) , n ∈ N 0 , i ∈ { 2 , 3 , 4 } , for meromorphic starlike functions of order α and meromorphic strongly starlike of order β . Similar estimates for meromorphic convex functions of order α ( 0 ≤ α < 1 ) and meromorphic strongly convex of order β ( 0 < β ≤ 1 ) are also discussed.

Orlicz lacunary sequence spaces of 𝑙-fractional difference operators

2020 ◽  
Vol 26 (2) ◽  
pp. 173-183
Author(s):  
Kuldip Raj ◽  
Kavita Saini ◽  
Anu Choudhary
Keyword(s):  
Difference Operator ◽  
Lacunary Sequence ◽  
Sequence Spaces ◽  
Difference Operators ◽  
Normed Spaces ◽  
Fractional Difference ◽  
New Approach ◽  
Inclusion Relations ◽  
Difference Sequence Spaces ◽  
Bounded Sequences

AbstractRecently, S. K. Mahato and P. D. Srivastava [A class of sequence spaces defined by 𝑙-fractional difference operator, preprint 2018, http://arxiv.org/abs/1806.10383] studied 𝑙-fractional difference sequence spaces. In this article, we intend to make a new approach to introduce and study some lambda 𝑙-fractional convergent, lambda 𝑙-fractional null and lambda 𝑙-fractional bounded sequences over 𝑛-normed spaces. Various algebraic and topological properties of these newly formed sequence spaces have been explored, and some inclusion relations concerning these spaces are also established. Finally, some characterizations of the newly formed sequence spaces are given.

scholarly journals A Subclass of Analytic Functions Related tok-Uniformly Convex and Starlike Functions

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Saqib Hussain ◽  
Akhter Rasheed ◽  
Muhammad Asad Zaighum ◽  
Maslina Darus
Keyword(s):  
Convolution Operator ◽  
Starlike Functions ◽  
Distortion Theorem ◽  
Open Unit ◽  
Uniformly Convex ◽  
Open Unit Disc ◽  
Coefficient Inequalities ◽  
Uniformly Starlike Functions ◽  
Convex And Starlike Functions ◽  
Uniformly Starlike

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.

scholarly journals On certain classes of meromorphically starlike functions

1995 ◽  
Vol 18 (3) ◽  
pp. 463-467
Author(s):  
Nak Eun Cho ◽  
Ji A. Kim
Keyword(s):  
Meromorphic Functions ◽  
Starlike Functions ◽  
New Class ◽  
Multiplier Transformation

The object of the present paper is to introduce a new class∑n(α)of meromorphic functions defined by a multiplier transformation and to investigate some properties for the class∑n(α)Further we study integrals of functions in∑n(α).

scholarly journals On sufficient conditions of meromorphic starlike functions

2014 ◽  
Vol 32 (2) ◽  
pp. 229
Author(s):  
Ali Muhammad
Keyword(s):  
Unit Disc ◽  
Sufficient Conditions ◽  
Starlike Functions ◽  
Meromorphic Starlike Functions

In this paper, we investigate interesting properties and sufficient conditions for meromorphic starlike functions in the punctured unit disc.

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