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Related papers: Third Hankel Determinant For A Class Of Starlike F…

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Let $\mathcal{H}$ be the class of harmonic functions $f=h+\overline{g}$ in the unit disk $\mathbb{D}:=\{z\in\mathbb{C}:|z|<1\}$, where $h$ and $g$ are analytic in $\mathbb{D}$ with the normalization $h(0)=g(0)=h'(0)-1=0$. Let…

Complex Variables · Mathematics 2026-04-14 Raju Biswas

In this paper, we obtain the sharp bounds of the second Hankel determinant of logarithmic inverse coefficients for the strongly starlike and strongly convex functions of order alpha.

Complex Variables · Mathematics 2023-09-22 Vasudevarao Allu , Amal Shaji

We introduce and study a class of starlike functions defined by \begin{equation*} \mathscr{S}^*_\wp:=\left\{f\in\mathcal{A}: \frac{zf'(z)}{f(z)}\prec 1+ze^z=:\wp(z)\right\}, \end{equation*} where $\wp$ maps the unit disk onto a cardioid…

Complex Variables · Mathematics 2022-08-23 S. Sivaprasad Kumar , Kamaljeet Gangania

In this article, we wish to establish some first order differential subordination relations for certain Carath\'{e}odory functions with nice geometrical properties. Moreover, several implications are determined so that the normalized…

Complex Variables · Mathematics 2021-03-09 Meghna Sharma , Sushil Kumar , Naveen Kumar Jain

The Hankel determinant $H_{2,1}(F_{f^{-1}}/2)$ of logarithmic coefficients is defined as: \begin{align*} H_{2,1}(F_{f^{-1}}/2):= \begin{vmatrix} \Gamma_1 & \Gamma_2 \Gamma_2 & \Gamma_3 \end{vmatrix}=\Gamma_1\Gamma_3-\Gamma^2_2, \end{align*}…

Complex Variables · Mathematics 2023-07-28 Sanju Mandal , Molla Basir Ahamed

In this paper, we consider the class of strongly bi-close-to-convex functions of order $\alpha$ and bi-close-to-convex functions of order $\beta$. We obtain an upper bound estimate for the second Hankel determinant for functions belonging…

Complex Variables · Mathematics 2021-03-30 S. Kanas , V. Sivasankari , O. Karthiyayini , S. Sivasubramanian

In the present investigation, we study the class of Sigmoid starlike functions, given by $\mathcal{S}^*_{SG}=\{f\in\mathcal{A}: {zf'(z)}/{f(z)}\prec 2/(1+e^{-z})\}$ in context of estimating the sharp radius constants associated with several…

Complex Variables · Mathematics 2022-08-03 Priyanka Goel , S. Sivaprasad Kumar

Logarithmic coefficients play a crucial role in the theory of univalent functions. In this study,we focus on the classes $\mathcal{S}_e^\ast$ and $\mathcal{C}_e$ of starlike and convex functions, respectively, \begin{align*}…

Complex Variables · Mathematics 2025-11-06 Sujoy Majumder , Nabadwip Sarkar , Molla Basir Ahamed

In this paper, we consider polynomials orthogonal with respect to a varying perturbed Laguerre weight $e^{-n(z-\log z+t/z)}$ for $t<0$ and $z$ on certain contours in the complex plane. When the parameters $n$, $t$ and the degree $k$ are…

Classical Analysis and ODEs · Mathematics 2016-01-20 Shuai-Xia Xu , Dan Dai , Yu-Qiu Zhao

We consider the class $\mathcal{S}^*(q_c)$ of normalized starlike functions $f$ analytic in the open unit disk $|z|<1$ that satisfying the inequality \begin{equation*} \left|\left(\frac{zf'(z)}{f(z)}\right)^2-1\right|<c \quad (0<c\leq1).…

Complex Variables · Mathematics 2018-07-11 R. Kargar , L. Trojnar-Spelina

We derive general formula for the fourth coefficient of the functions belonging to the Carath\'{e}odory class involving the parameters lying in the open unit disk. Further, we obtain sharp upper bounds of initial inverse coefficients for…

Complex Variables · Mathematics 2020-10-08 Priyanka Goel , S. Sivaprasad Kumar

In the present paper, the coefficient estimates are found for the class $\mathcal S^{*-1}(\alpha)$ consisting of inverses of functions in the class of univalent starlike functions of order $\alpha$ in $\mathcal D=\{z\in\mathbb C:|z|<1\}$.…

Complex Variables · Mathematics 2007-05-23 G. P. Kapoor , A. K. Mishra

In this paper, we introduce a new subclass of harmonic functions $f=s+\overline{t}$ in the open unit disk $U =\left \{ z\in C:\left \vert z\right \vert <1\right \} $ satisfying ${\text{Re}}\left[ \gamma s^{\prime }(z)+\delta zs^{\prime…

Complex Variables · Mathematics 2021-07-09 Serkan Çakmak , Elif Yaşar , Sibel Yalçın

Siegel-Shidlovskii theory of $E$-functions involves a non-vanishing proof for the determinants attached to the linear forms $D^kR(t)$, derivatives of an auxiliary function $R(t)$. Let a non-zero function $F(t)$ satisfy $m$th order linear…

Number Theory · Mathematics 2022-09-27 Tapani Matala-aho

A starlike univalent function $f$ is characterized by the function $zf'(z)/f(z)$; several subclasses of these functions were studied in the past by restricting the function $zf'(z)/f(z)$ to take values in a region $\Omega$ on the right-half…

Complex Variables · Mathematics 2021-01-06 Shalu Yadav , Kanika Sharma , V. Ravichandran

In this paper, we investigate the sharp bounds of the second Hankel determinant of Logarithmic coefficients for the starlike and convex functions with respect to symmetric points in the open unit disk.

Complex Variables · Mathematics 2021-12-07 Vasudeavarao Allu , Vibhuti Arora , Amal Shaji

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

For every $q\in(0,1)$ and $0\le \alpha<1$ we define a class of analytic functions, the so-called $q$-starlike functions of order $\alpha$, on the open unit disk. We study this class of functions and explore some inclusion properties with…

Complex Variables · Mathematics 2015-09-14 Sarita Agrawal , Swadesh K. Sahoo

In this paper we study class $\mathcal{S}^+$ of univalent functions $f$ such that $\frac{z}{f(z)}$ has real and positive coefficients. For such functions we give estimates of the Fekete-Szeg\H{o} functional and sharp estimates of their…

Complex Variables · Mathematics 2018-10-17 Milutin Obradovic , Nikola Tuneski

In this paper, we consider the Hankel determinants associated with the singularly perturbed Laguerre weight $w(x)=x^\alpha e^{-x-t/x}$, $x\in (0, \infty)$, $t>0$ and $\alpha>0$. When the matrix size $n\to\infty$, we obtain an asymptotic…

Classical Analysis and ODEs · Mathematics 2014-11-06 Shuai-Xia Xu , Dan Dai , Yu-Qiu Zhao
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