scholarly journals On Harmonic Functions Defined by Differential Operator with Respect tok-Symmetric Points

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Afaf A. Ali Abubaker ◽  
Maslina Darus
Keyword(s):  
Differential Operator ◽  
Representation Theorem ◽  
Harmonic Functions ◽  
Univalent Functions ◽  
Distortion Theorem ◽  
Coefficient Condition ◽  
Symmetric Points

We introduce new classesMHkσ,s(λ,δ,α)andM¯Hkσ,s(λ,δ,α)of harmonic univalent functions with respect tok-symmetric points defined by differential operator. We determine a sufficient coefficient condition, representation theorem, and distortion theorem.

scholarly journals A Class of k-Symmetric Harmonic Functions Involving a Certain q-Derivative Operator

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1812
Author(s):  
Hari M. Srivastava ◽  
Nazar Khan ◽  
Shahid Khan ◽  
Qazi Zahoor Ahmad ◽  
Bilal Khan
Keyword(s):  
Harmonic Functions ◽  
Univalent Functions ◽  
Function Class ◽  
Distortion Theorem ◽  
Additional Parameter ◽  
Sufficient Condition ◽  
Closure Properties ◽  
Derivative Operator ◽  
New Class ◽  
Symmetric Points

In this paper, we introduce a new class of harmonic univalent functions with respect to k-symmetric points by using a newly-defined q-analog of the derivative operator for complex harmonic functions. For this harmonic univalent function class, we derive a sufficient condition, a representation theorem, and a distortion theorem. We also apply a generalized q-Bernardi–Libera–Livingston integral operator to examine the closure properties and coefficient bounds. Furthermore, we highlight some known consequences of our main results. In the concluding part of the article, we have finally reiterated the well-demonstrated fact that the results presented in this article can easily be rewritten as the so-called (p,q)-variations by making some straightforward simplifications, and it will be an inconsequential exercise, simply because the additional parameter p is obviously unnecessary.

scholarly journals Applications of $ q $-difference symmetric operator in harmonic univalent functions

2021 ◽  
Vol 7 (1) ◽  
pp. 667-680
Author(s):  
Caihuan Zhang ◽  
◽  
Shahid Khan ◽  
Aftab Hussain ◽  
Nazar Khan ◽  
...  
Keyword(s):  
Differential Operator ◽  
Operator Theory ◽  
Harmonic Functions ◽  
Symmetric Operator ◽  
Univalent Functions ◽  
Coefficient Bounds ◽  
New Class ◽  
Coefficient Condition ◽  
Distortion Theorems ◽  
First Time

<abstract><p>In this paper, for the first time, we apply symmetric $ q $ -calculus operator theory to define symmetric Salagean $ q $-differential operator. We introduce a new class $ \widetilde{\mathcal{H}}_{q}^{m}\left(\alpha \right) $ of harmonic univalent functions $ f $ associated with newly defined symmetric Salagean $ q $-differential operator for complex harmonic functions. A sufficient coefficient condition for the functions $ f $ to be sense preserving and univalent and in the same class is obtained. It is proved that this coefficient condition is necessary for the functions in its subclass $ \overline{\widetilde{\mathcal{H}}_{q}^{m}\left(\alpha \right) } $ and obtain sharp coefficient bounds, distortion theorems and covering results. Furthermore, we also highlight some known consequence of our main results.</p></abstract>

scholarly journals On Fully-Convex Harmonic Functions and their Extension

2018 ◽  
Vol 38 (2) ◽  
pp. 51-60
Author(s):  
Shahpour Nosrati ◽  
Ahmad Zireh
Keyword(s):  
Harmonic Functions ◽  
Univalent Functions ◽  
Sufficient Conditions ◽  
Open Unit ◽  
Open Unit Disk ◽  
Uniformly Convex ◽  
Circular Arc ◽  
Coefficient Condition ◽  
Necessary And Sufficient ◽  
Convex Univalent Functions

‎Uniformly convex univalent functions that introduced by Goodman‎, ‎maps every circular arc contained in the open unit disk with center in it into a convex curve‎. ‎On the other hand‎, ‎a fully-convex harmonic function‎, ‎maps each subdisk $|z|=r<1$ onto a convex curve‎. ‎Here we synthesis these two ideas and introduce a family of univalent harmonic functions which are fully-convex and uniformly convex also‎. ‎In the following we will mention some examples of this subclass and obtain a necessary and sufficient conditions and finally a coefficient condition will attain with convolution‎.

scholarly journals A class of harmonic functions associated with a generalized differential operator

2020 ◽  
Vol 108 (122) ◽  
pp. 145-154
Author(s):  
Sarika Verma ◽  
Deepali Khurana ◽  
Raj Kumar
Keyword(s):  
Differential Operator ◽  
Harmonic Functions ◽  
Univalent Functions ◽  
Extreme Points ◽  
Coefficient Estimates ◽  
Geometric Properties ◽  
New Class ◽  
Inclusion Relations ◽  
Generalized Differential

We introduce a new class of harmonic univalent functions by using a generalized differential operator and investigate some of its geometric properties, like, coefficient estimates, extreme points and inclusion relations. Finally, we show that this class is invariant under Bernandi-Libera-Livingston integral for harmonic functions.

scholarly journals A Subclass of Harmonic Univalent Functions Defined by Salagean Integro Differential Operator

2020 ◽  
Vol 25 (3) ◽  
pp. 62-70
Author(s):  
Hasan Bayram
Keyword(s):  
Differential Operator ◽  
Harmonic Functions ◽  
Univalent Functions ◽  
Distortion Bounds ◽  
Coefficient Inequalities

In this paper, we scrutinize some fundamental features of a subclass of harmonic functions defined by a new operator. Like coefficient inequalities, convex combinations, distortion bounds.

Coefficient inequalities for new subclasses of bi-univalent functions defined by using the function fδ

2021 ◽  
Author(s):  
Fatma Sağsöz ◽  
Halit Orhan
Keyword(s):  
Differential Operator ◽  
Univalent Functions ◽  
Function Classes ◽  
Coefficient Inequalities

In this investigation, we introduce and study two new subclasses of bi-univalent functions defined by using the function [Formula: see text] and Salagean differential operator. Furthermore, we find estimates on the coefficients [Formula: see text] and [Formula: see text] for these function classes.

scholarly journals Some Janowski Type Harmonic q-Starlike Functions Associated with Symmetrical Points

Mathematics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 629 ◽  
Author(s):  
Muhammad Arif ◽  
Omar Barkub ◽  
Hari Srivastava ◽  
Saleem Abdullah ◽  
Sher Khan
Keyword(s):  
Differential Operator ◽  
Harmonic Functions ◽  
Sufficient Conditions ◽  
Starlike Functions ◽  
Partial Sums ◽  
Circular Region ◽  
Necessary And Sufficient ◽  
New Criterion ◽  
Symmetrical Points ◽  
Convexity Conditions

The motive behind this article is to apply the notions of q-derivative by introducing some new families of harmonic functions associated with the symmetric circular region. We develop a new criterion for sense preserving and hence the univalency in terms of q-differential operator. The necessary and sufficient conditions are established for univalency for this newly defined class. We also discuss some other interesting properties such as distortion limits, convolution preserving, and convexity conditions. Further, by using sufficient inequality, we establish sharp bounds of the real parts of the ratios of harmonic functions to its sequences of partial sums. Some known consequences of the main results are also obtained by varying the parameters.

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