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We present some completely monotonic functions involving the$q$-polygamma functions, our result generalizes some known results.

Classical Analysis and ODEs · Mathematics 2016-01-22 Peng Gao

Motivated by existing results, we present some completely monotonic functions involving the polygamma functions.

Classical Analysis and ODEs · Mathematics 2010-12-03 Peng Gao

Associated to a holomorphic quadratic differential is a unit ball of the measured lamination space. The Thurston volume of the unit ball defines a function on the moduli space. We show that the volume function is not proper and characterize…

Complex Variables · Mathematics 2025-10-27 Weixu Su , Shenxing Zhang

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 article, a necessary and sufficient condition and a necessary condition are established for a function involving the gamma function to be logarithmically completely monotonic on $(0,\infty)$. As applications of the necessary and…

Classical Analysis and ODEs · Mathematics 2012-08-21 Senlin Guo , Feng Qi

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

For a broad class of integral functionals defined on the space of $n$-dimensional convex bodies, we establish necessary and sufficient conditions for monotonicity, and necessary conditions for the validity of a Brunn-Minkowski type…

Metric Geometry · Mathematics 2016-02-22 Andrea Colesanti , Daniel Hug , Eugenia Saorín-Gómez

We consider $k$-dimensional central sections of the unit ball of $\ell_p^n$ (denoted $B_p^n$) and we prove that their volume are bounded by the volume of $B_p^n$ whenever $1<p<2$ and $1\le k\le (n-1)/2$ or $k=n-1$. We also consider $0<p<1$…

Functional Analysis · Mathematics 2007-05-23 Jesus Bastero , Fernando Galve , Ana Pena , Miguel Romance

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 paper, the authors establish an inequality involving exponential functions and sums, introduce a ratio of many gamma functions, discuss properties, including monotonicity, logarithmic convexity, (logarithmically) complete…

Classical Analysis and ODEs · Mathematics 2021-01-05 Feng Qi , Wen-Hui Li , Shu-Bin Yu , Xin-Yu Du , Bai-Ni Guo

In the paper, the authors review origins, motivations, and generalizations of a series of inequalities involving several exponential functions and sums, establish three new inequalities involving finite exponential functions and sums by…

Classical Analysis and ODEs · Mathematics 2020-08-26 Feng Qi , Bai-Ni Guo

We offer an alternative and shorter proof to a result by Jan J.Ub{\o}e about monotonicity properties of a one-dimensional function that appeared in the Mathematical Intelligencer in 2015. Our proof is based on reducing the problem to…

Classical Analysis and ODEs · Mathematics 2018-11-26 Bernd Kawohl , David Krejčiřík

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

The aim of this work is to expose some asymptotic series associated to some expressions involving the volume of the n-dimensional unit ball. All proofs and the methods used for improving the classical inequalities announced in the final…

Classical Analysis and ODEs · Mathematics 2015-01-08 Cristinel Mortici

In this manuscript, we present the complete monotonicity of functions defined in terms of the poly-double gamma function \begin{align*} \psi_2^{(n)}(x) = (-1)^{n+1} n! \sum_{k=0}^{\infty} \dfrac{(1+k)}{(x+k)^{n+1}}, \quad x > 0, \ n\geq 2.…

General Mathematics · Mathematics 2025-11-12 Deepshikha Mishra , A. Swaminathan

In this article, we present a new two-dimensional generalization of the gamma function based on the product of the one-dimensional generalized beta function and the one-dimensional generalized gamma function. As will become clear later,…

General Mathematics · Mathematics 2024-03-18 Artem M. Ponomarenko

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

The aim of this paper is to develop analytic techniques to deal with certain monotonicity of combinatorial sequences. (1) A criterion for the monotonicity of the function $\sqrt[x]{f(x)}$ is given, which is a continuous analog for one…

Combinatorics · Mathematics 2015-04-29 Bao-Xuan Zhu

In this note we study the monotonicity of the function $x\mapsto \psi(1 +bx)^a/\psi(1 + ax)^b$. We also give the several inequalities involving the psi function, whic is the logarithmic derivative of the gamma function.

Classical Analysis and ODEs · Mathematics 2015-09-08 Barkat Ali Bhayo