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Related papers: On some complete monotonic functions

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A class of functions involving the divided differences of the psi function and the polygamma functions and originating from Kershaw's double inequality are proved to be completely monotonic. As applications of these results, the…

Classical Analysis and ODEs · Mathematics 2011-05-13 Feng Qi , Bai-Ni Guo

We prove some new results and unify the proofs of old ones involving complete monotonicity of expressions involving gamma and $q$-gamma functions, $0 < q < 1$. Each of these results implies the infinite divisibility of a related probability…

Classical Analysis and ODEs · Mathematics 2013-01-10 Mourad E. H. Ismail , Martin E. Muldoon

In the paper, the authors establish integral representations of some functions related to the remainder of Burnside's formula for the gamma function and find the (logarithmically) complete monotonicity of these and related functions. These…

Classical Analysis and ODEs · Mathematics 2014-04-01 Feng Qi

We present some completely monotonic functions involving the $q$-gamma function that are inspired by their analogues involving the gamma function.

Classical Analysis and ODEs · Mathematics 2010-11-16 Peng Gao

In the paper, the authors establish three kinds of double inequalities for the trigamma function in terms of the exponential function to powers of the digamma function. These newly established inequalities extend some known results. The…

Classical Analysis and ODEs · Mathematics 2015-12-17 Feng Qi , Cristinel Mortici

In this paper we present several new classes of logarithmically completely monotonic functions. Our functions have in common that they are defined in terms of the $q-$gamma and $q-$digamma functions. As an applications of this results, some…

Classical Analysis and ODEs · Mathematics 2015-12-21 Khaled Mehrez

In this paper, we prove logarithmically complete monotonicity properties of certain ratios of the $k$-gamma function. As a consequence, we deduce some inequalities involving the $k$-gamma and $k$-trigamma functions.

General Mathematics · Mathematics 2019-02-08 Kwara Nantomah , Li Yin

In this paper, some monotonicity and concavity results of several functions involving the psi and polygamma functions are proved, and then some known inequalities are extended and generalized.

Classical Analysis and ODEs · Mathematics 2010-08-03 Feng Qi , Bai-Ni Guo

In the paper the author provides necessary and sufficient conditions on $a$ for the function $\frac{1}{2}\ln(2\pi)-x+\bigl(x-\frac{1}{2}\bigr)\ln x-\ln\Gamma(x)+\frac1{12}{\psi'(x+a)}$ and its negative to be completely monotonic on…

Classical Analysis and ODEs · Mathematics 2016-08-02 Feng Qi

In the present paper, we establish necessary and sufficient conditions for the functions $x^\alpha\bigl\lvert\psi^{(i)}(x+\beta)\bigr\lvert$ and $\alpha\bigl\lvert\psi^{(i)}(x+\beta)\bigr\lvert-x\bigl\lvert\psi^{(i+1)}(x+\beta)\bigr\lvert$…

Classical Analysis and ODEs · Mathematics 2010-07-12 Feng Qi , Senlin Guo , Bai-Ni Guo

In this paper, we study some properties such as the monotonicity, logarithmically complete monotonicity, logarithmic convexity, and geometric convexity, of the combinations of gamma function and power function. The results we obtain…

Classical Analysis and ODEs · Mathematics 2022-05-26 Peipei Du , Gendi Wang

This paper is an enhanced version of a more than decade-older paper with a similar title. Many formulae involving both finite and infinite sums of digamma and polygamma functions up to quadratic order, few of which appear in standard…

Classical Analysis and ODEs · Mathematics 2017-10-17 Michael Milgram

Motivated by several conjectures posed in the paper "F. Qi and A.-Q. Liu, Completely monotonic degrees for a difference between the logarithmic and psi functions, J. Comput. Appl. Math., vol. 361, pp. 366--371 (2019); available online at…

Classical Analysis and ODEs · Mathematics 2022-01-20 Feng Qi , Mansour Mahmoud

In this paper, we introduce a new two-parameter deformation of the Gamma function that generalizes some existing Gamma-type functions in the literature. We study properties of this function that depend on the parameters. We also prove some…

Classical Analysis and ODEs · Mathematics 2025-10-10 Anton Asare-Tuah , Emmanuel Djabang , Eyram A. K. Schwinger , Benoit F. Sehba , Ralph A. Twum

We investigate conditions for logarithmic complete monotonicity of product ratios of gamma and q-gamma functions whose arguments are linear functions of the variable. We give necessary and sufficient conditions in terms of nonnegativity of…

Classical Analysis and ODEs · Mathematics 2020-04-30 Christian Berg , Asena Cetinkaya , Dmitrii Karp

In the article, a notion "logarithmically absolutely monotonic function" is introduced, an inclusion that a logarithmically absolutely monotonic function is also absolutely monotonic is revealed, the logarithmically complete monotonicity…

Classical Analysis and ODEs · Mathematics 2010-08-20 Feng Qi , Bai-Ni Guo

An inequality, which combines the concept of completely monotone functions with the theory of divided differences, is proposed. It is a straightforward generalization of a result, recently introduced by two of the present authors.

Classical Analysis and ODEs · Mathematics 2022-04-15 Vasiliki Bitsouni , Nikolaos Gialelis , Dan-Stefan Marinescu

In this article, logarithmically complete monotonicity properties of some functions such as $\frac1{[\Gamma(x+1)]^{1/x}}$, $\frac{[{\Gamma(x+\alpha+1)}]^{1/(x+\alpha)}}{[{\Gamma(x+1)}]^{1/x}}$, $\frac{[\Gamma(x+1)]^{1/x}}{(x+1)^\alpha}$ and…

Classical Analysis and ODEs · Mathematics 2010-08-03 Feng Qi , Bai-Ni Guo

In the paper, the author establishes inequalities, monotonicity, convexity, and unimodality for functions concerning the modified Bessel functions of the first kind and compute the completely monotonic degrees of differences between the…

Classical Analysis and ODEs · Mathematics 2014-12-02 Feng Qi

In the paper, the author studies properties of three functions relating to the exponential function and the existence of partitions of unity, including accurate and explicit computation of their derivatives, analyticity, complete…

Classical Analysis and ODEs · Mathematics 2023-01-04 Feng Qi