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353,625 Results Found

  • Essay
  • Open Access
1,594 Views
14 Pages

28 November 2025

Two theories that align with and support Usage-based approaches to language acquisition are Functionalism, which motivates the communicative functions of form-meaning connections produced by grammatical phenomena, and Connectionism, which provides a...

  • Article
  • Open Access
5 Citations
2,635 Views
16 Pages

20 April 2023

We calculate some infinite sums containing the digamma function in closed form. These sums are related either to the incomplete beta function or to the Bessel functions. The calculations yield interesting new results as by-products, such as parameter...

(This article belongs to the Special Issue Analytical and Computational Methods in Differential Equations, Special Functions, Transmutations and Integral Transforms)
  • Article
  • Open Access
11 Citations
3,044 Views
21 Pages

Some Results of Extended Beta Function and Hypergeometric Functions by Using Wiman’s Function

  • Shilpi Jain,
  • Rahul Goyal,
  • Praveen Agarwal,
  • Antonella Lupica and
  • Clemente Cesarano

18 November 2021

The main aim of this research paper is to introduce a new extension of the Gauss hypergeometric function and confluent hypergeometric function by using an extended beta function. Some functional relations, summation relations, integral representation...

(This article belongs to the Special Issue Orthogonal Polynomials and Special Functions)
  • Article
  • Open Access
9 Citations
1,847 Views
13 Pages

11 January 2024

In this study, we introduce the new subclasses, Mα(sin) and Mα(cos), of α-convex functions associated with sine and cosine functions. First, we obtain the initial coefficient bounds for the first five coefficients of the functions t...

(This article belongs to the Special Issue Current Topics in Geometric Function Theory)
  • Article
  • Open Access
2 Citations
1,091 Views
16 Pages

Hypergeometric Functions as Activation Functions: The Particular Case of Bessel-Type Functions

  • Nelson Vieira,
  • Felipe Freitas,
  • Roberto Figueiredo and
  • Petia Georgieva

9 July 2025

The choice of the activation functions in neural networks (NN) are of paramount importance in the training process and the performance of NNs. Therefore, the machine learning community has directed its attention to the development of computationally...

  • Article
  • Open Access
1 Citations
500 Views
13 Pages

On Functional Independence of Beurling Zeta-Functions

  • Antanas Laurinčikas and
  • Darius Šiaučiūnas

7 May 2026

Let P be a system of generalized prime numbers, and NP the corresponding system of generalized integers. Assuming that ∑m⩽xm∈NP1−ax≪xβ with a>0 and 0⩽β<1, we consider the Beurling zeta-function &zeta...

(This article belongs to the Special Issue Applications in Functional Analysis)
  • Article
  • Open Access
3 Citations
2,692 Views
14 Pages

On Coefficient Functionals for Functions with Coefficients Bounded by 1

  • Paweł Zaprawa,
  • Anna Futa and
  • Magdalena Jastrzębska

1 April 2020

In this paper, we discuss two well-known coefficient functionals a 2 a 4 − a 3 2 and a 4 − a 2 a 3 . The first one is called the Hankel determinant of order 2. The second one is a special case of Zalcman fun...

(This article belongs to the Special Issue Complex Analysis and Its Applications)
  • Article
  • Open Access
1,216 Views
12 Pages

27 January 2025

This paper shows that certain F43 hypergeometric functions can be expanded in sums of pair products of F21 functions. In special cases, the F43 hypergeometric functions reduce to F32 functions. Further special cases allow one to reduce the F32 functi...

  • Article
  • Open Access
27 Citations
4,713 Views
11 Pages

An Extension of Beta Function by Using Wiman’s Function

  • Rahul Goyal,
  • Shaher Momani,
  • Praveen Agarwal and
  • Michael Th. Rassias

16 August 2021

The main purpose of this paper is to study extension of the extended beta function by Shadab et al. by using 2-parameter Mittag-Leffler function given by Wiman. In particular, we study some functional relations, integral representation, Mellin transf...

(This article belongs to the Special Issue Special Functions Associated with Fractional Calculus)
  • Article
  • Open Access
6 Citations
2,789 Views
11 Pages

25 January 2021

In this paper, we further study the generating function involving a variety of special numbers and ploynomials constructed by the second author. Applying the Mellin transformation to this generating function, we define a new class of zeta type functi...

  • Article
  • Open Access
2 Citations
4,291 Views
34 Pages

On Functional Hamilton–Jacobi and Schrödinger Equations and Functional Renormalization Group

  • Mikhail G. Ivanov,
  • Alexey E. Kalugin,
  • Anna A. Ogarkova and
  • Stanislav L. Ogarkov

10 October 2020

We consider the functional Hamilton–Jacobi (HJ) equation, which is the central equation of the holographic renormalization group (HRG), functional Schrödinger equation, and generalized Wilson–Polchinski (WP) equation, which is the ce...

(This article belongs to the Special Issue Symmetry in Quantum Systems)
  • Article
  • Open Access
1 Citations
1,430 Views
17 Pages

7 August 2024

The principal aim of this paper is to introduce the extended Voigt-type function Vμ,ν(x,y) and its counterpart extension Wμ,ν(x,y), involving the Neumann function Yν in the kernel of the representing integral. The newly defined integra...

(This article belongs to the Special Issue Orthogonal Polynomials, Special Functions and Applications: 2nd Edition)
  • Review
  • Open Access
5 Citations
6,849 Views
18 Pages

Objectives: The objective of this narrative review was to examine the available literature regarding the increasingly popular method of exercise commonly referred to as “Functional Training” and its potential implications on vestibular an...

(This article belongs to the Section Kinesiology and Biomechanics)
  • Article
  • Open Access
3 Citations
1,003 Views
10 Pages

Relations of Harmonic Starlike Function Subclasses with Mittag–Leffler Function

  • Naci Taşar,
  • Fethiye Müge Sakar,
  • Seher Melike Aydoğan and
  • Georgia Irina Oros

26 November 2024

In this study, the connection between certain subfamilies of harmonic univalent functions is established by utilizing a convolution operator involving the Mittag–Leffler function. The investigation reveals inclusion relations concerning harmoni...

(This article belongs to the Special Issue New Developments in Geometric Function Theory, 3rd Edition)
  • Article
  • Open Access
1 Citations
983 Views
13 Pages

11 January 2026

This paper aims to obtain the Ψηξ-extended Whittaker function and its integral representations. This function is defined by using the Ψηξ-confluent hypergeometric function, which was recently extended in terms of the Fox–W...

  • Article
  • Open Access
366 Views
13 Pages

3 July 2026

This paper examines the relationship between the classical polylogarithm function and meromorphic harmonic univalent mappings. Using a convolution operator derived from the polylogarithm function, we define a class of harmonic meromorphic functions a...

(This article belongs to the Special Issue New Advances in Complex Analysis and Functional Analysis)
  • Article
  • Open Access
4 Citations
2,128 Views
13 Pages

2 August 2024

In this paper, taking into account the intriguing recent results of Rabotnov functions, Poisson functions, Bessel functions and Wright functions, we consider a new comprehensive subclass Oμ(Δ1,Δ2,Δ3,Δ4) of univalent functio...

(This article belongs to the Special Issue Symmetry in Geometric Theory of Analytic Functions)
  • Article
  • Open Access
8 Citations
2,452 Views
12 Pages

30 June 2021

In this paper, some coefficient problems for starlike analytic functions with respect to symmetric points are considered. Bounds of several coefficient functionals for functions belonging to this class are provided. The main aim of this paper is to f...

  • Article
  • Open Access
1 Citations
2,575 Views
17 Pages

18 March 2024

This paper shows that certain 3F4 hypergeometric functions can be expanded in sums of pair products of 2F3 functions, which reduce in special cases to 2F3 functions expanded in sums of pair products of 1F2 functions. This expands...

(This article belongs to the Special Issue Advances in Generalized Hypergeometric Functions, Integral Transforms and Number Theory)
  • Article
  • Open Access
1 Citations
2,173 Views
32 Pages

On Certain Analytic Functions Associated with Nephroid Function

  • Wahid Ullah,
  • Rabia Fayyaz,
  • Daniel Breaz and
  • Luminiţa-Ioana Cotîrlă

14 February 2025

The normalized analytic function ΦN(z)=1+z−z33, which connects the open unit disk onto a bounded domain within the right half of a nephroid-shaped region, is associated with the bounded turning of functions denoted by Rn. It calculates the...

(This article belongs to the Special Issue Recent Advances in Complex Analysis and Related Topics)
  • Feature Paper
  • Article
  • Open Access
1,223 Views
12 Pages

26 September 2024

Relying on the Hurwitz formula, we find closed-form formulas for the series over sine and cosine functions through the Hurwitz zeta functions, and using them and another summation formula for trigonometric series, we obtain a finite sum for some seri...

  • Article
  • Open Access
122 Citations
5,269 Views
14 Pages

Some General Classes of q-Starlike Functions Associated with the Janowski Functions

  • Hari M. Srivastava,
  • Muhammad Tahir,
  • Bilal Khan,
  • Qazi Zahoor Ahmad and
  • Nazar Khan

23 February 2019

By making use of the concept of basic (or q-) calculus, various families of q-extensions of starlike functions of order α in the open unit disk U were introduced and studied from many different viewpoints and perspectives. In this p...

(This article belongs to the Special Issue Integral Transforms and Operational Calculus)
  • Article
  • Open Access
7 Citations
2,490 Views
17 Pages

On the Fekete–Szegö Type Functionals for Close-to-Convex Functions

  • Katarzyna Tra̧bka-Wiȩcław,
  • Paweł Zaprawa,
  • Magdalena Gregorczyk and
  • Andrzej Rysak

10 December 2019

In this paper, we consider two functionals of the Fekete–Szegö type Θ f ( μ ) = a 4 − μ a 2 a 3 and Φ f ( μ ) = a 2 a 4 − μ a 3 2 for a real number μ and fo...

  • Article
  • Open Access
3 Citations
3,413 Views
9 Pages

On the Relation between Lambert W-Function and Generalized Hypergeometric Functions

  • Pushpa Narayan Rathie and
  • Luan Carlos de Sena Monteiro Ozelim

23 November 2022

In the theory of special functions, finding correlations between different types of functions is of great interest as unifying results, especially when considering issues such as analytic continuation. In the present paper, the relation between Lambe...

  • Article
  • Open Access
6 Citations
2,680 Views
21 Pages

Starlike Functions Associated with Secant Hyperbolic Function

  • Khadija Bano,
  • Mohsan Raza,
  • Qin Xin,
  • Fairouz Tchier and
  • Sarfraz Nawaz Malik

16 March 2023

Motivated by the recent work on the symmetric domains, this article investigates certain features of symmetric domain which are caused by the secant hyperbolic functions. Geometric characteristics of analytic functions associated with secant hyperbol...

(This article belongs to the Special Issue Selected Papers from International Symposium on Geometric Function Theory and Applications (GFTA))
  • Article
  • Open Access
2,274 Views
20 Pages

28 November 2023

In existing models with an unknown link function, the issue of predictors containing both multiple functional data and multiple scalar data has not been studied. To fill this gap, we propose a generalized partially functional linear model, which not...

(This article belongs to the Special Issue Advances in Mathematics: Theory and Applications)
  • Article
  • Open Access
2 Citations
1,448 Views
13 Pages

8 December 2022

The Lerch zeta function is defined by a Dirichlet series depending on two fixed parameters. In the paper, we consider the approximation of analytic functions by discrete shifts of the Lerch zeta function, and we prove that, for arbitrary parameters a...

  • Article
  • Open Access
259 Views
12 Pages

4 September 2026

Plateaued Boolean functions play an important role in sequence design and cryptography due to their favorable properties such as high nonlinearity, resilience and low additive autocorrelation. In this paper, by modifying the support of certain quadra...

(This article belongs to the Special Issue Mathematical Foundations in Public Key Cryptography and Privacy Computing)
  • Article
  • Open Access
12 Citations
3,160 Views
19 Pages

Subclasses of Analytic Functions Subordinated to the Four-Leaf Function

  • Saravanan Gunasekar,
  • Baskaran Sudharsanan,
  • Musthafa Ibrahim and
  • Teodor Bulboacă

27 February 2024

The purpose of this research is to unify and extend the study of the well-known concept of coefficient estimates for some subclasses of analytic functions. We define the new subclass A4r,s of analytic functions related to the four-leaf domain, to inc...

(This article belongs to the Special Issue Advances in Geometric Function Theory and Related Topics)
  • Article
  • Open Access
11 Citations
1,455 Views
16 Pages

27 May 2024

Geometric function theory has extensively explored the geometric characteristics of analytic functions within symmetric domains. This study analyzes the geometric properties of a specific class of analytic functions employing confluent hypergeometric...

(This article belongs to the Special Issue Symmetries of Difference Equations, Special Functions and Orthogonal Polynomials II)
  • Article
  • Open Access
2 Citations
989 Views
12 Pages

21 October 2025

In this paper we will be concerned with zeta-symmetry—the functional equation for the (Riemann) zeta-function (equivalents to which are called modular relations)—and reveal the reason why so many results are intrinsic to PFE (Partial Frac...

(This article belongs to the Special Issue Special Functions and Related Topics, 2nd Edition)
  • Article
  • Open Access
2 Citations
1,650 Views
17 Pages

27 August 2024

The Geometric Theory of Analytic Functions was initially developed for the space of functions that are analytic in the unit disk. The convexity and starlikeness of functions are the first geometric ideas considered in this theory. We can notice a sym...

  • Article
  • Open Access
3 Citations
1,683 Views
13 Pages

Bi-Concave Functions Connected with the Combination of the Binomial Series and the Confluent Hypergeometric Function

  • Hari M. Srivastava,
  • Sheza M. El-Deeb,
  • Daniel Breaz,
  • Luminita-Ioana Cotîrlă and
  • Grigore Stefan Sălăgean

13 February 2024

In this article, we first define and then propose to systematically study some new subclasses of the class of analytic and bi-concave functions in the open unit disk. For this purpose, we make use of a combination of the binomial series and the confl...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
7 Citations
4,318 Views
19 Pages

There has been a considerable evolution of the theory of fractal interpolation function (FIF) over the last three decades. Recently, we introduced a multivariate analogue of a special class of FIFs, which is referred to as α-fractal functions, from t...

(This article belongs to the Special Issue Fractal Functions and Applications)
  • Article
  • Open Access
16 Citations
2,208 Views
16 Pages

Problems Concerning Coefficients of Symmetric Starlike Functions Connected with the Sigmoid Function

  • Muhammad Imran Faisal,
  • Isra Al-Shbeil,
  • Muhammad Abbas,
  • Muhammad Arif and
  • Reem K. Alhefthi

21 June 2023

In numerous geometric and physical applications of complex analysis, estimating the sharp bounds of coefficient-related problems of univalent functions is very important due to the fact that these coefficients describe the core inherent properties of...

(This article belongs to the Special Issue Symmetry in Functional Equations and Analytic Inequalities III)
  • Article
  • Open Access
4 Citations
1,237 Views
8 Pages

Toeplitz Matrices for a Class of Bazilevič Functions and the λ-Pseudo-Starlike Functions

  • Abbas Kareem Wanas,
  • Salam Abdulhussein Sehen and
  • Ágnes Orsolya Páll-Szabó

2 August 2024

In the present paper, we define and study a new family of holomorphic functions which involve the Bazilevič functions and the λ-pseudo-starlike functions. We establish coefficient estimates for the first four determinants of the symmetric...

(This article belongs to the Special Issue Advances in Geometric Function Theory and Related Topics)
  • Article
  • Open Access
1 Citations
2,614 Views
21 Pages

The two-parameter Wright special function is an interesting mathematical object that arises in the theory of the space and time-fractional diffusion equations. Moreover, many other special functions are particular instantiations of the Wright functio...

(This article belongs to the Special Issue Fractional Differential Operators with Classical and New Memory Kernels)
  • Article
  • Open Access
4 Citations
779 Views
25 Pages

Geometric Attributes of Analytic Functions Generated by Mittag-Leffler Function

  • Ekram E. Ali,
  • Rabha M. El-Ashwah,
  • Wafaa Y. Kota and
  • Abeer M. Albalahi

14 October 2025

This study examines the necessary requirements for some analytic function subclasses, especially those associated with the generalized Mittag-Leffler function, to be classified as univalent function subclasses that are determined by particular geomet...

(This article belongs to the Special Issue Advanced Research in Complex Analysis Operators and Special Classes of Analytic Functions)
  • Article
  • Open Access
20 Citations
3,432 Views
11 Pages

25 December 2021

A refined asymptotics of the Jacobi theta functions and their logarithmic derivatives have been received. The asymptotics of the Nevanlinna characteristics of the indicated functions and the arbitrary elliptic function have been found. The estimation...

(This article belongs to the Special Issue Analytic Functions and Nonlinear Functional Analysis)
  • Article
  • Open Access
3 Citations
1,564 Views
12 Pages

Joint Approximation of Analytic Functions by Shifts of Lerch Zeta-Functions

  • Antanas Laurinčikas,
  • Toma Mikalauskaitė and
  • Darius Šiaučiūnas

2 February 2023

In this paper, we consider the simultaneous approximation of tuples of analytic functions by tuples of shifts of Lerch zeta-functions with arbitrary parameters. We prove that there exists a closed set of tuples of functions analytic in the right-hand...

(This article belongs to the Special Issue Analytic Methods in Number Theory and Allied Fields)
  • Article
  • Open Access
739 Views
16 Pages

20 April 2026

In this article, we study scalar-on-function regression with functional covariates observed through replicated measurements subject to measurement error. Treating replicated curves as surrogates of an underlying latent process, the proposed framework...

(This article belongs to the Special Issue Statistical Learning and Data Science: Methods, Theory, and Applications)
  • Article
  • Open Access
10 Citations
5,138 Views
13 Pages

It is difficult to determine whether lung function improves by simple abdominal strengthening exercises, and studies on the correlation of lung function and functional movement are insufficient. Therefore; we aimed to identify the correlation between...

(This article belongs to the Special Issue Comprehensive Clinical Physiotherapy and Rehabilitation)
  • Article
  • Open Access
2 Citations
2,365 Views
22 Pages

On the Study of Starlike Functions Associated with the Generalized Sine Hyperbolic Function

  • Baseer Gul,
  • Muhammad Arif,
  • Reem K. Alhefthi,
  • Daniel Breaz and ,
  • Luminiţa-Ioana Cotîrlă and
  • Eleonora Rapeanu
  • + 1 author+ 0 author

1 December 2023

Geometric function theory, a subfield of complex analysis that examines the geometrical characteristics of analytic functions, has seen a sharp increase in research in recent years. In particular, by employing subordination notions, the contributions...

(This article belongs to the Special Issue Complex Analysis and Geometric Function Theory, 2nd Edition)
  • Article
  • Open Access
10 Citations
3,721 Views
23 Pages

COVID-19 Data Imputation by Multiple Function-on-Function Principal Component Regression

  • Christian Acal,
  • Manuel Escabias,
  • Ana M. Aguilera and
  • Mariano J. Valderrama

28 May 2021

The aim of this paper is the imputation of missing data of COVID-19 hospitalized and intensive care curves in several Spanish regions. Taking into account that the curves of cases, deceases and recovered people are completely observed, a function-on-...

(This article belongs to the Section D1: Probability and Statistics)
  • Article
  • Open Access
434 Views
14 Pages

13 July 2026

In this paper, we introduce and investigate a new subclass of bi-univalent Bazilevič-type functions associated with the Gregory generating function. The proposed class is defined by means of subordination and depends on the parameters ν and &...

(This article belongs to the Section C4: Complex Analysis)
  • Article
  • Open Access
2 Citations
1,934 Views
14 Pages

20 July 2024

A challenging part of studying geometric function theory is figuring out the sharp boundaries for coefficient-related problems that crop up in the Taylor–Maclaurin series of univalent functions. Using Caputo-type fractional derivatives to defin...

(This article belongs to the Special Issue Geometric Function Theory and Applications―Festschrift for Grigore-Stefan Salagean's 75th Birthday)
  • Article
  • Open Access
1 Citations
2,648 Views
23 Pages

19 July 2022

We investigate a nonparametric, varying coefficient regression approach for modeling and estimating the regression effects caused by two functionally correlated datasets. Due to modern biomedical technology to measure multiple patient features during...

(This article belongs to the Special Issue New Advances in High-Dimensional and Non-asymptotic Statistics)
  • Article
  • Open Access
1 Citations
1,167 Views
21 Pages

In this work, we provide a convolution type operator Λν,b that is produced by the generalized Marcum Q-function and examine how it maps to various Janowski-type subclasses of harmonic univalent functions. Since the Marcum Q-function has an...

(This article belongs to the Special Issue Fractional Calculus, Quantum Calculus and Special Functions in Complex Analysis)

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