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Related papers: Differential Subordinations for Starlike Functions…

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Functions with fixed initial coefficient have been widely studied. A new methodology is proposed in this paper by making appropriate modifications and improvements to the theory of second-order differential subordination. Several…

Complex Variables · Mathematics 2012-08-02 Rosihan M. Ali , Sumit Nagpal , V. Ravichandran

Consider a function $f : \mathbb{T} \to \mathbb{C}$, $n$-times differentiable on $\mathbb{T}$ and such that its $n$th derivative $f^{(n)}$ is bounded but not necessarily continuous. Let $U : \mathbb{R} \to \mathcal{U}(\mathcal{H})$ be a…

Functional Analysis · Mathematics 2024-06-21 Clément Coine

Let $h$ and $g$ be two analytic functions in the unit disc $\Delta$ that $g(0)=1$. Also let $\beta$ be a complex number with ${\rm Re}\{\beta\}>-1/2$. A function $f$ is said to be log--harmonic mapping if it has the following representation…

Complex Variables · Mathematics 2019-06-20 Rahim Kargar , Hesam Mahzoon

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…

Complex Variables · Mathematics 2017-04-27 Nirupam Ghosh , A. Vasudevarao

In this paper, we study analytic and geometric properties of the solution $q(z)$ to the differential equation $q(z)+zq'(z)/q(z)=h(z)$ with the initial condition $q(0)=1$ for a given analytic function $h(z)$ on the unit disk $|z|<1$ in the…

Complex Variables · Mathematics 2015-12-11 Ming Li , Toshiyuki Sugawa

Let $S^{*}(1-b)$ ($b \not= 0$ complex) denote the class of functions $f(z)=z+\alpha_{2}z^{2}+...$ analytic in $D={z \mid | z | < 1}$ which satisfies,for $z=e^{i\theta} \in D$, $(f(z)/z)\not= 0$ in D, and $Re \Biggr [ 1+ {1 \over b} \Biggr…

Complex Variables · Mathematics 2016-09-07 Yasar Polatoglu , Metin Bolcal , Arzu Sen

This paper is devoted to studying the first-order variational analysis of non-convex and non-differentiable functions that may not be subdifferentially regular. To achieve this goal, we entirely rely on two concepts of directional…

Optimization and Control · Mathematics 2022-04-22 Ashkan Mohammadi

In a previous paper \cite{ref1} we produced a sequence of analytic functions $\{\alpha \uparrow^n z\}_{n=0}^\infty$ when $1 \le \alpha \le e^{1/e}$ and $z$ was in the right half of the complex plane, the \emph{bounded analytic…

Complex Variables · Mathematics 2016-04-07 James D. Nixon

We define an analogue of the Baernstein star function for a meromorphic function f in several complex variables. This function is subharmonic on the upper half-plane and encodes some of the main functionals attached to f.We then…

Complex Variables · Mathematics 2017-02-01 Faruk Abi-Khuzam , Florian Bertrand , Giuseppe Della Sala

Let $\mathcal{A}$ denote the class of analytic functions $f$ in the unit disk $\mathbb{D}=\{z\in\mathbb{C}:|z|<1\}$ normalized by $f(0)=0$, $f'(0)=1$. For $-\pi/2<\alpha<\pi/2$, let $\mathcal{S}_{\alpha}$ be the subclass of $\mathcal{A}$…

Complex Variables · Mathematics 2023-07-19 Md Firoz Ali , Sanjit Pal

Let $f$ be a transcendental meromorphic function defined in the complex plane $\mathbb{C}$, and $\varphi(\not\equiv 0,\infty)$ be a small function of $f$. In this paper, We give a quantitative estimation of the characteristic function $T(r,…

Complex Variables · Mathematics 2020-08-31 Weiran Lü , Bikash Chakraborty

Let $\mathcal{V}_p(\lambda)$ be the collection of all functions $f$ defined in the unit disc $\ID$ having a simple pole at $z=p$ where $0<p<1$ and analytic in $\ID\setminus\{p\}$ with $f(0)=0=f'(0)-1$ and satisfying the differential…

Complex Variables · Mathematics 2017-12-11 Bappaditya Bhowmik , Firdoshi Parveen

In this paper, we obtain some application of first-order differential subordination, superordination and sandwich-type results involving operator for certain normalized $p$-valent analytic functions. Further, properties of $p$-valent…

Complex Variables · Mathematics 2018-11-09 V. S. Masih , A. Ebadian , Sh. Najafzadeh

Let -1\leq B<A\leq 1. Condition on \beta, is determined so that 1+\beta zp'(z)/p^k(z)\prec(1+Az)/(1+Bz)\;(-1<k\leq3) implies p(z)\prec \sqrt{1+z}. Similarly, condition on \beta is determined so that 1+\beta zp'(z)/p^n(z) or p(z)+\beta…

Complex Variables · Mathematics 2013-03-04 S. Sivaprasad Kumar , Virendra Kumar , V. Ravichandran , Nak Eun Cho

We consider the family of all analytic and univalent functions in the unit disk of the form $f(z)=z+a_2z^2+a_3z^3+\cdots$. Our objective in this paper is to estimate the difference of the moduli of successive coefficients, that is $\big |…

Complex Variables · Mathematics 2019-03-26 Vibhuti Arora , Saminathan Ponnusamy , Swadesh Kumar Sahoo

Let $\phi$ be a normalized convex function defined on open unit disk $\mathbb{D}$. For a unified class of normalized analytic functions which satisfy the second order differential subordination $f'(z)+ \alpha z f''(z) \prec \phi(z)$ for all…

Complex Variables · Mathematics 2020-12-29 Swati Anand , Naveen Kumar Jain , Sushil Kumar

Some sufficient conditions on certain constants which are involved in some first, second and third order differential subordinations associated with certain functions with positive real part like modified Sigmoid function, exponential…

Complex Variables · Mathematics 2020-12-24 Meghna Sharma , Sushil Kumar , Naveen Kumar Jain

We establish, for $1 < p < \infty$, higher order $\mathcal{S}^p$-differentiability results of the function $\varphi : t\in \mathbb{R} \mapsto f(A+tK) - f(A)$ for selfadjoint operators $A$ and $K$ on a separable Hilbert space $\mathcal{H}$…

Functional Analysis · Mathematics 2019-06-14 Clément Coine

For $0\leq\alpha\leq 1,$ let $H_{\alpha}(x,y)$ be the convex weighted harmonic mean of $x$ and $y.$ We establish differential subordination implications of the form \begin{equation*} H_{\alpha}(p(z),p(z)\Theta(z)+zp'(z)\Phi(z))\prec…

Complex Variables · Mathematics 2022-03-23 S. Sivaprasad Kumar , Priyanka Goel

Let ${\mathcal M}$ be the class of analytic functions in the unit disk $\ID$ with the normalization $f(0)=f'(0)-1=0$, and satisfying the condition $$\left |z^2\left (\frac{z}{f(z)}\right )''+ f'(z)\left(\frac{z}{f(z)} \right)^{2}-1\right…

Complex Variables · Mathematics 2019-05-07 Rosihan M. Ali , Milutin Obradović , Saminathan Ponnusamy