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Gamma Function

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The Gamma function is a mathematical function that extends the concept of factorial to complex and non-integer numbers. It is defined for positive real numbers as \( \Gamma(n) = (n-1)! \) and is represented by the integral \( \Gamma(z) = \int_0^{\infty} t^{z-1} e^{-t} dt \) for complex numbers with a positive real part.
lightbulbAbout this topic
The Gamma function is a mathematical function that extends the concept of factorial to complex and non-integer numbers. It is defined for positive real numbers as \( \Gamma(n) = (n-1)! \) and is represented by the integral \( \Gamma(z) = \int_0^{\infty} t^{z-1} e^{-t} dt \) for complex numbers with a positive real part.

Key research themes

1. How can the Gamma function be generalized and extended to unify special functions and address applications in fractional calculus and applied sciences?

Research on generalizing the Gamma function focuses on developing extended integral and series formulations with additional parameters or structures. These advances enable connections to fractional calculus operators, new special functions (e.g., k-gamma, generalized Mittag-Leffler), and wider classes of applications including stochastic models, diffraction, and physical processes. This theme is vital for enhancing the analytical toolkit provided by the Gamma function and for capturing more complex phenomena mathematically.

Key finding: The study proposes a novel generalized gamma function defined via infinite products involving powers of logarithms and connects this construction to generalized Euler-Mascheroni constants. It establishes essential properties... Read more
Key finding: This paper introduces the k-version of the Bessel function built on the k-gamma function, a generalization of the classical gamma. It demonstrates relationships between the k-Bessel function and other extended functions like... Read more

2. What are the properties and inequalities involving derivatives and expansions of generalized Gamma-related functions and their parameter dependencies?

Many investigations target the behavior of the Gamma function and its generalizations through asymptotic expansions, bounds, monotonicity, and derivatives with respect to parameters—especially in the context of special functions like digamma, trigamma, and the Whittaker functions. These studies develop inequalities, completely monotonic properties, and analytic expansions that inform approximation, numerical evaluation, and theoretical insights critical to mathematical analysis and applied problems.

Key finding: The authors derive a detailed asymptotic expansion for a class of generalized gamma functions Γ_μ(v) involving parameter μ. They rigorously demonstrate the function's completely monotonic properties with respect to its... Read more
Key finding: Extending classical inequalities for the Gamma and digamma functions, this paper proves that the trigamma function ψ'(z) exhibits geometric convexity (GG-convexity) and GA-convexity on (0, ∞). Among its main results is that... Read more
Key finding: This paper systematically derives parameter derivatives of the Whittaker M function via confluent hypergeometric function expansions. The differentiation leads to infinite series involving quotients of digamma and gamma... Read more
Key finding: Extending the previous work on Whittaker parameter derivatives, this study analyzes the W variant of Whittaker functions with respect to κ and μ parameters. It develops infinite series and integral analytic formulae,... Read more

3. How do the Gamma function and its variants inform probability distributions, statistical modeling, and applications in data analysis?

The Gamma function underpins numerous continuous probability distributions, including gamma, beta, chi-square, F, Student’s t, and various logistic distributions. Research in this theme develops new modified or generalized Gamma-based models and investigates their probabilistic properties, parameter estimation methods, and applications to real-world data such as medical statistics, reliability, and environmental processes. This theme highlights the Gamma function’s foundational role in statistical theory and applied data analysis.

Key finding: The authors propose a modified Gamma (MG) distribution introducing a risk intensity control to modulate the right tail behavior for data exhibiting light tails relative to classical gamma. They derive analytical properties of... Read more
Key finding: This paper unifies and extends type I and II generalized logistic distributions by introducing the gamma generalized logistic distribution (GGLD) with three parameters, capturing skewness and kurtosis flexibility. The authors... Read more
Key finding: This paper reviews the derivation of several fundamental continuous probability distributions—including gamma, beta, chi-square, Student’s t, and F distributions—directly via the Euler Gamma function. The expository work... Read more

All papers in Gamma Function

Examen (sujet+corrigé) de Probabilités et Statistique en Licence de Mathématique 3ème année, sur les thèmes : - loi géométrique, loi binomiale négative, - fonction de répartition - fonction génératrice, somme de deux variables aléatoires... more
Examen (sujet+corrigé) de Probabilités et Statistique en Licence de Mathématique 3ème année, sur les thèmes : - loi de Bernoulli, loi binomiale, loi exponentielle, loi de Poisson, loi normale - espérance conditionnelle - fonction... more
Examen (sujet+corrigé) de Probabilités et Statistique en Licence de Mathématique 3ème année, sur les thèmes : - loi uniforme, loi exponentielle symétrique - fonction de survie, fonction de répartition, convergence en loi - fonction... more
This paper addresses the prominent field of research concerning recurrence relations for special functions. Recognizing the significance of this area, we present a novel contribution by introducing new recurrence relations specifically... more
This paper addresses the prominent field of research concerning recurrence relations for special functions. Recognizing the significance of this area, we present a novel contribution by introducing new recurrence relations specifically... more
We establish a new natural extension of Mittag-Leffler function with three variables which is so called "trivariate Mittag-Leffler function". The trivariate Mittag-Leffler function can be expressed via complex integral representation by... more
Examen (sujet+corrigé) de Probabilités en Licence de Mathématique 3ème année : - exercice 1 : loi normale, théorème du transfert - exercice 2 : loi de Cauchy, fonction caractéristique, convergence en loi - exercice 3 : loi géométrique,... more
Examen (sujet+énoncé) de Probabilités en Licence de Mathématique 3ème année, sur les thèmes : - loi géométrique, loi uniforme sur [0,1], loi exponentielle, loi gamma - espérance conditionnelle - fonction de répartition, fonction... more
Examen (sujet+corrigé) de Probabilités en Licence de Mathématique 3ème année, sur les thèmes :
- loi uniforme sur [0,1], loi exponentielle, loi de Rayleigh, loi gamma
- fonction caractéristique, convergence en loi, Théorème Central Limite
Examen (sujet+corrigé) de Probabilités en Licence de Mathématique 3ème année : - exercice 1 : loi normale, fonction caractéristique, convergence en loi d'une suite de variables aléatoires - exercice 2 : fonction de répartition et... more
Examen (énoncé+corrigé) en Licence de Mathématique, 3ème année - exercice 1 (probabilités) : loi géométrique - exercice 2 (probabilités) : loi uniforme discrète - exercice 3 (probabilités) : loi de Poisson - problème (statistique) :... more
Examen (sujet+corrigé) en Licence de Mathématique, 3ème année
- exercice 1 (probabilités) : loi exponentielle
- exercice 2 (probabilités) : loi géométrique
- problème (statistique) : estimation de paramètre pour une loi de Gumbel
Estimation du paramètre θ > 0 d'une loi apparentée à la loi exponentielle. Problème d'examen (sujet+corrigé) en Probabilités et Statistique, Licence de Mathématique 3ème année. Les premières questions sont analogues à celles du sujet de... more
Estimation du paramètre θ > 0 d'une fonction densité f définie par : f (t) = 3 t^2 /θ^3 sur [0,θ]. Problème d'examen (sujet+corrigé) en Probabilités et Statistique, Licence de Mathématique, 3ème année
Estimation de paramètre pour une loi exponentielle symétrique.

Problème d'examen (énoncé+corrigé) en Probabilités et Statistique, Licence de Mathématique 3ème année
Estimation de paramètre pour une loi uniforme.
Problème d'examen (sujet+corrigé) dans le cadre de l'enseignement "Probabilités et Statistique" en Licence de Mathématique 3ème année
Estimation de paramètre pour une loi apparentée à la loi exponentielle. C'est un sujet d'examen (énoncé+corrigé) pour l'enseignement "Probabilités et Statistique" en Licence de Mathématique 3ème année
Estimation du paramètre inconnu λ > 0 d'une loi exponentielle.

Problème d'examen (énoncé+corrigé) dans le cadre de l'enseignement "Probabilités et Statistique" en Licence de Mathématique 3ème année
Estimation du paramètre (écart-type) d'une loi normale centrée.

C'est un problème (énoncé +corrigé) pour des étudiants en Licence de Mathématique 3ème année, dans le cadre de l'enseignement "Probabilités et Statistique"
Most of the errors in the original paper had to do with saying that certain functions related to the q-gamma function were not completely monotonic. We discovered these errors through reading the paper Some completely monotonic functions... more
In this paper we analyze the behavior of the Gamma function at its critical points and points of discontinuity on the negative side of the x-axis. We will also explain the bluntness of the gamma function on this negative side.
We consider a beam problem with a polynomial source and a boundary damping of order between 0 and 1. Sufficient conditions on the initial data are established to have blow up of solutions in finite time.
We consider a beam problem with a polynomial source and a boundary damping of order between 0 and 1. Sufficient conditions on the initial data are established to have blow up of solutions in finite time.
In this paper, we study the completely monotonic property of two functions involving the function (x) = [ψ (x)] 2 + ψ (x) and deduce the double inequality which improve some recent results, where ψ(x) is the logarithmic derivative of the... more
The Prime Number Theorem tells us π(N) ∼ N / ln(N), but rarely provides systematic explanations for why prime density necessarily tends to zero. This paper proposes five mathematical principles of prime rarefaction: the Multiplicative... more
This paper explores an intuitive argument for the plausibility of the Goldbach Conjecture, examining how its assumed truth implies a necessary distribution of prime numbers.
In this simple paper, a small refinement to the Prime Number Theorem (PNT) [1] is proposed, which allows us to limit the error with which said theorem predicts the value of the Prime-counting function π(x); and, in this way, endorse the... more
Matrix functions with potential applications have a major role in science and engineering. One of the fundamental matrix functions, which is particularly important due to its connections with certain matrix differential equations and... more
In this article, generalized pathway integral operator with the classical Gauss hypergeometric function kernel and the fractional differential operators are used to studied new extended hypergeometric function. Furthermore, extended... more
A simple proof of Ramanujan's formula for the Fourier transform of |Γ(a + it)| 2 is given where a is fixed and has positive real part and t is real. The result is extended to other values of a by solving an inhomogeneous ODE and we use it... more
In the present research note, we define a new extension of beta function by making use of the multi-index Mittag-Leffler function. Here, first we derive its fundamental properties and then we present a new type of beta distribution as an... more
In this paper, by introducing two sequences of new numbers and their derivatives, which are closely related to the Stirling numbers of the first kind, and choosing to employ six known generalized Kummer’s summation formulas for 2F1(−1)... more
Kurepa’s hypothesis for the left factorial has been an unsolved problem for more than 50 years. In this paper, we have proposed new equivalents for Kurepa’s hypothesis for the left factorial. The connection between the left factorial and... more
An extension of Euler's beta function, analogous to the recent generalization of Euler's gamma function and Riemann's zeta function, for which the usual properties and representation are naturally and simply extended, is introduced. It is... more
We prove a conjecture of Saffari on the distribution of the angular speed of ultraflat sequences of unimodular polynomials.
Littlewood polynomials are polynomials with each of their coefficients in the set {-1, 1}. We compute asymptotic formulas for the arithmetic mean values of the Mahler's measure and the L p norms of Littlewood polynomials of degree n -1.... more
We prove the following conjecture of Saffari (1991): that is, the polynomial P n (z) and its "conjugate reciprocal" P * n (z) = n k=0 a n-k,n z k become "nearly orthogonal" as n → ∞ . To this end we use results from where (as well as in... more
We prove a conjecture of Saffari on the distribution of the angular speed of ultraflat sequences of unimodular polynomials.
A wavelet-based method to extract coherent bursts out of turbulent signals is presented. The signal is projected onto an orthogonal wavelet basis, a threshold is applied to the wavelet coefficients, and the denoised signal is... more
In an attempt to give extensions of certain results in the theory of Mac-Robert's ^-function and Meijer's (7-function, the integrals (i) and (ii) P ^A -l # ( 2()j £ 2y(2<)(? (l)| JO I
Cylindrical pipes are widely used in industries such as nuclear power plants and micro total analysis systems (mTAS). Measuring the flow rate of fluid in such pipes is critical. Ultrasonic flowmeters are noncontact, nondestructive, and... more
We construct a non-trivial, even, entire function F (s) such that the quotient F (s)/Γ(s) remains bounded on the right half-plane ℜ(s) > 0. The construction is based solely on the classical Euler Gamma function and elementary functions,... more
It is shown that an integral representation for the extension of a general Hurwitz-Lerch zeta function recently obtained by [5] is a special case of the closed form integral expression for the Mathieu (a, λ)-series given by Pogány ( )... more
The purpose of the present paper is to study certain radii problems for the function , where β is a positive real number, γ is a complex number such that γ +β = 0 and the function F (z) varies various subclasses of analytic functions with... more
We examined two subjectively distinct memory states that are elicited during recognition memory in humans and compared them in terms of the gamma oscillations (20-60 Hz) in the electroencepahalogram (EEG) that they induced. These... more
We derive solvability conditions and closed-form solution for the Weber type integral equation, related to the familiar Weber-Orr integral transforms and the old Weber-Titchmarsh problem (posed in Proc. Lond. Math. Soc. 22(2) (1924),... more
This paper presents a new approximation for the prime counting function, denoted π(x), which counts the number of prime numbers less than x. While the classical approximation P (x) ≈ x ln x (Prime Number Theorem) is widely used, we... more
We introduce a novel modular resonance approach to the Riemann Hypothesis by constructing a modified zeta function, ζ_mod(s), derived from a deterministic sieve of modular prime residues. This function admits full analytic continuation,... more
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