11 - The Gamma, Beta, Pi, and Psi Functions

In this present paper, first, we investigate a new generalized Pochhammer's symbol and its various properties in terms of a new symbol $(s; k)$, where $s; k > 0$. Then, we define a new generalization of gamma and beta functions and their various associated properties in the form of $(s; k)$. Also, we define a new generalization of hypergeometric functions and develop differential equations for generalized hypergeometric functions in the form of $(s; k)$. We present that generalized hypergeometric functions are the solution of the said differential equation. Furthermore, some useful results and properties and integral representation related to these generalized Pochhammer's symbol, gamma function, beta function, and hypergeometric functions are presented.

Considering the equations for some functions involving the first or the second derivatives of the biconfluent Heun function, we construct two expansions of the solutions of the biconfluent Heun equation in terms of incomplete Beta functions. The first series applies single Beta functions as expansion functions, while the second one involves a combination of two Beta functions. The coefficients of expansions obey four- and five-term recurrence relations, respectively. It is shown that the proposed technique is potent to produce series solutions in terms of other special functions. Two examples of such expansions in terms of the incomplete Gamma functions are presented.

In this paper, several properties associated with inequalities and the logarithmically complete monotonicity of functions related to the gamma and psi functions and the Barnes G-function are obtained. Relevant connections of the results presented here with those derived in earlier works are also pointed out.

In this paper, we introduce the notion of completely mixed monotonicity of a function of several variables, very few of which have appeared. We give a necessary and sufficient condition for a function constructed by ratios of gamma functions to be completely mixed monotonic. From this, some new inequalities for gamma, psi, and polygamma functions are derived.

This work aimed to review the literature on probability density functions (pdf) and adjustment methods used to predict the diametric distribution of trees in native forests in Brazil, from 1973 to 2018. Articles published in scientific journals were selected, with open access, which addressed the pdf theme and adjustment methods for predicting the diameter distribution of trees in native forests. The searches were carried out on the Web of Science, Science Direct, Scopus, Google Scholar and MDPI platforms. The results of the literature review showed that the Weibull, Beta and Gamma probability density functions were the most used in studies of the diametric distribution of trees in native forests in Brazil. Among them, the maximum likelihood adjustment method was the most used, followed by the percentile method. Furthermore, the Beta function, introduced by Pearson, and the Gamma function, with parameters α and β, were addressed. Furthermore, adherence tests, such as Anderson-Darling, Kolmogorov-Smirnov, Reynolds, Cramér-von Mises, Chi-square and Shapiro-Wilk, were used to evaluate the goodness of fit of the pdfs.

We explore a number of functional properties of the $q$-gamma function and a class of its quotients; including the $q$-beta function. We obtain formulas for all higher logarithmic derivatives of these quotients and give precise conditions on their sign. We prove how these and other functional properties, such as the multiplication formula or the asymptotic expansion, together with the fundamental functional equation of the $q$-gamma function uniquely define those functions. We also study reciprocal "relatives" of the fundamental $q$-gamma functional equation, and prove uniqueness of solution results for them. In addition, we also use a reflection formula of Askey to derive expressions relating the classical sine function and the number $\pi$ to the $q$-gamma function. Throughout we highlight the similarities and differences between the cases $0<q<1$ and $q>1$.

Some properties of functions related to the gamma, psi and tetragamma functions

A mode of teaching where students receive all information passively from a lecturer is ineffective in fostering of conceptual understanding of statistics. One mode of teaching which engages learners in the learning process of statistics is e-learning. This study was therefore, designed to determine the effect and challenges of e-learning on students at Mukuba University. The study employed quasi-experimental design. Sample for the study consisted of 60 third year students of mathematics studying statistics. Self-made questionnaire and statistics performance tests were used to collect data for the study. Students in the experimental group learnt Gamma and Beta Function, and Probability Distributions of Function of Random Variable using E-Learning approach while students in the control group learnt Gamma and Beta Function, and Probability Distributions of Function of Random Variable using conventional learning approach. Data for the study was analyzed using independent sample t-test statistics. The null hypothesis (H0) was tested at 5 percent significance level. The findings of the study revealed that E-Learning approach improved students' academic performance. Based on this, this study recommended that E-Learning should be used as an alternative method in teaching of statistics.

A class of functions involving divided differences of the psi and tri-gamma functions and originating from Kershaw's double inequality are proved to be completely monotonic. As applications of these results, the monotonicity and convexity of a function involving the ratio of two gamma functions and originating from the establishment of the best upper and lower bounds in Kershaw's double inequality are derived, two sharp double inequalities involving ratios of double factorials are recovered, the probability integral or error function is estimated, a double inequality for ratio of the volumes of the unit balls in <TEX>$\mathbb{R}^{n-1}$</TEX> and <TEX>$\mathbb{R}^n$</TEX> respectively is deduced, and a symmetrical upper and lower bounds for the gamma function in terms of the psi function is generalized.

Probability theory can be understood as a particular field in mathematics. Hence, it is only to be expected that it relies intensely on theory from analysis and algebra. For example, the fact that the cumulative probability over all values a random variable can assume has to be equal to one is not always feasible to check for without a profound knowledge of mathematics. Continuous probability distributions involve a good deal of analysis and the more sophisticated a distribution is, the more mathematics is necessary to handle it.

This article provides an overview of the exact closed-form solutions for purely nonlinear oscillators. These solutions comprise the period of vibration and free and forced responses for one-degree-of-freedom systems. The use of special function for this purpose is demonstrated which includes: beta function, gamma function, hypergeometric function, Ateb function, Jacobi amplitude and Jacobi elliptic function.

The radiative correction to beta function is comprehensively studied at 1 loop in the context of universal extra dimensions. Instead of using cutoffs to regularize 1-loop divergences, the dimensional regularization scheme is used. Large momenta effects are removed from physical amplitudes by adjusting the parameters of the appropriate counterterms. The use of a SU(N)-covariant gauge-fixing procedure is stressed. 1-loop contributions of KK excitations are characterized by discrete KK sums and continuous momenta sums, which can diverge. Two types of UVs are identified, one arising from poles of the gamma function and associated with short-distance effects in the usual 4-dimensional spacetime manifold, and the other emerging either from poles of the 1-dimensional Epstein function or from the gamma function, and corresponding to short-distance effects in the compact manifold. We address the cases of 5 and 4+n dimensions (n>1) separately. In 5 dimensions the 1-dimensional Epstein function is convergent, so the usual counterterm renormalizes the vacuum polarization function. For 4+n dimensions, the 1-dimensional Epstein function is divergent, so renormalization is implemented by interactions of canonical dimension higher than 4, already present in the effective theory. The polarization function is renormalized using both mass-dependent and mass-independent schemes, with extra-dimensions effects decoupling in the former case but not in the latter. The beta function is calculated for an arbitrary number of extra dimensions. Our main result is that Yang-Mills theory remains perturbative at 1 loop, which is in disagreement with the results obtained in the literature by using a cutoff regulator, which suggest that Yang-Mills theory in more than 4 dimensions ceases to be perturbative. We emphasize the advantages of a mass-dependent scheme in this type of theories, in which decoupling is manifest.

In this paper, some new integrals involving k gamma function and k digamma function have been established. An integral is established involving k gamma function, and its special values are discussed. Similarly, some new integrals have been established for k digamma function, and different elementary function is associated with it for different values of k. A nice representation of the Euler-Mascheroni constant and π in the form of k digamma function for different values of k is also obtained.

Like the gamma and psi functions, the functions treated in this chapter are among the most important of the special functions.

Numerous special functions, including the beta function, hypergeometric functions, and other orthogonal polynomials, are closely connected to the gamma function. Recently, gamma function has been enhanced by adding a new parameter. As a consequence, this gamma is called the parametric gamma function or b-gamma function. By utilizing the enhanced gamma function (or the parametric gamma function), we have present a generalization for the special function Rabotnov function. Consequently, new fractal-fractional operators (derivative and integral) involving the generalized Rabotnov function are defined. Analysis is introduced to discover the main properties of the suggested operators. Since the main challenge in the calculus of fractal-fractional operators is to design examples, we illustrate a set of examples including power series. We explore the boundedness of the recommended operators. There are many gains for checking the boundedness of fractal operators in general and fractal-fractional operators in particular. Moreover, as an application, we establish the existence and uniqueness solution of abstract fractal-fractional equation. Examples are presented at the end of the effort. Graphics and computations are observed using MATHEMATICA 13.3 software.•By using the parametric gamma function, the Rabotnov special function is generalized. New fractal-fractional operators are presented using the generalized Rabotnov function with examples;•Boundedness of these operators is investigated, where bounded operators give a strong foundation for understanding linear transformations across normed spaces, with many applications in science and mathematics.•Conditions of the existence and uniqueness of solutions of fractal-fractional differential abstract equation are established.