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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

A normalized univalent function is uniformly convex if it maps every circular arc contained in the open unit disk with center in it into a convex curve. This article surveys recent results on the class of uniformly convex functions and on…

Complex Variables · Mathematics 2011-08-23 R. M. Ali , V. Ravichandran

In the present investigation, certain subclasses of close-to-convex functions are investigated. In particular, we obtain an estimate for the Fekete-Szeg\"o functional for functions belonging to the class, distortion, growth estimates and…

Complex Variables · Mathematics 2011-12-30 Nak Eun Cho , Oh Sang Kwon , V. Ravichandran

It has been recently discovered that a convex function can be determined by its slopes and its infimum value, provided this latter is finite. The result was extended to nonconvex functions by replacing the infimum value by the set of all…

Functional Analysis · Mathematics 2025-10-21 Aris Daniilidis , David Salas , Sebastián Tapia-García

The first part of the paper provides new characterizations of the normal cone to the effective domain of the supremum of an arbitrary family of convex functions. These results are applied in the second part to give new formulas for the…

Optimization and Control · Mathematics 2020-12-10 R. Correa , A. Hantoute , M. A. López

We introduce three classes of analytic functions with fixed second coefficient which are defined using the class $\mathcal{P}$ of analytic functions with positive real part. The objective is to determine radii such that the three classes…

Complex Variables · Mathematics 2022-07-07 Shalini Rana , Om Ahuja , Naveen Kumar Jain

In this work, we establish some abstract results on the perspective of the fractional Musielak-Sobolev spaces, such as: uniform convexity, Radon-Riesz property with respect to the modular function, $(S_{+})$-property, Brezis-Lieb type Lemma…

Analysis of PDEs · Mathematics 2023-01-12 J. C. de Albuquerque , L. R. S. de Assis , M. L. M. Carvalho , A. Salort

In this paper, we study classes of discrete convex functions: submodular functions on modular semilattices and L-convex functions on oriented modular graphs. They were introduced by the author in complexity classification of minimum…

Optimization and Control · Mathematics 2016-10-11 Hiroshi Hirai

In this article, we further explore convex functions by revealing new bounds, resulting from stronger convexity behavior. In particular, we define the so called radical convex functions and study their properties. We will see that such…

Functional Analysis · Mathematics 2020-10-13 Mohammad Sababheh , Hamid Reza Moradi

Denote by $\mathcal{P}_{\log}$ the set of all non-constant Pick functions $f$ whose logarithmic derivatives $f^{\, \prime}/f$ also belong to the Pick class. Let $\mathcal{U}(\Lambda)$ be the family of functions $z\cdot f(z)$, where $f…

Classical Analysis and ODEs · Mathematics 2018-04-12 Andrew Bakan , Stephan Ruscheweyh , Luis Salinas

In this paper, we provide a number of subdifferential formulas for a class of nonconvex infimal convolutions in normed spaces. The formulas obtained unify several results on subdifferentials of the distance function and the minimal time…

Optimization and Control · Mathematics 2013-12-31 Nguyen Mau Nam

We consider the family of all meromorphic functions $f$ of the form $$ f(z)=\frac{1}{z}+b_0+b_1z+b_2z^2+\cdots $$ analytic and locally univalent in the puncture disk $\mathbb{D}_0:=\{z\in\mathbb{C}:\,0<|z|<1\}$. Our first objective in this…

Complex Variables · Mathematics 2017-09-05 Vibhuti Arora , Swadesh Kumar Sahoo

The torsion function of a convex planar domain has convex level sets, but explicit formulae are known only for rectangles and ellipses. Here we study the torsion function on convex planar domains of high eccentricity. We obtain an…

Analysis of PDEs · Mathematics 2018-12-04 Thomas Beck

The sharp bound for the third Hankel determinant for the coefficients of the inverse function of starlike function of order $1/2$ is obtained. In light of this, we can deduce that the functionals $|H_3(1)(f)|$ and $|H_3(1)(f^{-1})|$ exhibit…

Complex Variables · Mathematics 2023-07-07 Molla Basir Ahamed , Partha Pratim Roy

We give a local characterization of the class of functions having positive distributional derivative with respect to $\bar{z}$ that are almost everywhere equal to one of finitely many analytic functions and satisfy some mild non-degeneracy…

Complex Variables · Mathematics 2009-09-29 Julius Borcea , Rikard Bøgvad

The purpose of this paper is to deepen the study of the Pr\"ufer $\star$--multiplication domains, where $\star$ is a semistar operation. For this reason, in Section 2, we introduce the $\star$--domains, as a natural extension of the…

Commutative Algebra · Mathematics 2007-05-23 Marco Fontana , Giampaolo Picozza

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

For positive definite matrices $A$ and $B$, the Araki-Lieb-Thirring inequality amounts to an eigenvalue log-submajorisation relation for fractional powers $$\lambda(A^t B^t) \prec_{w(\log)} \lambda^t(AB), \quad 0<t\le 1,$$ while for…

Functional Analysis · Mathematics 2013-04-23 Koenraad M. R. Audenaert

The theory of slice regular (also called hyperholomorphic) functions is a generalization of complex analysis originally given in the quaternionic framework, and then further extended to Clifford algebras, octonions, and to real alternative…

Complex Variables · Mathematics 2025-12-02 Xinyuan Dou , Ming Jin , Guangbin Ren , Irene Sabadini

Some geometric properties of a normalized hyper-Bessel functions are investigated. Especially we focus on the radii of starlikeness, convexity, and uniform convexity of hyper-Bessel functions and we show that the obtained radii satisfy some…

Complex Variables · Mathematics 2021-01-19 İbrahim Aktaş , Árpád Baricz , Sanjeev Singh