Complete monotonicity of a function involving the p-psi function and alternative proofs

Authors

  • Valmir Krasniqi

    Department of Mathematics, University of Prishtina, Prishtine 10000, Republic of Kosova

  • Feng Qi

    Department of Mathematics, College of Science, Tianjin Polytechnic University Tianjin City, 300160, China

How to Cite

Krasniqi, V., & Qi, F. (2014). Complete monotonicity of a function involving the p-psi function and alternative proofs. Global Journal of Mathematical Analysis, 2(3), 204-208. https://doi.org/10.14419/gjma.v2i3.3096

Received date: June 30, 2014

Accepted date: July 26, 2014

Published date: August 3, 2014

DOI:

https://doi.org/10.14419/gjma.v2i3.3096

Abstract

In the paper, the authors prove that the function $x^\alpha\big[\ln\frac{px}{x+p+1}-\psi_p(x)\big]$ is completely monotonic on $(0,\infty)$ if and only if $\alpha \le 1$, where $p\in\mathbb{N}$ and $\psi_p(x)$ is the $p$-analogue of the classical psi function $\psi(x)$.

Keywords: completely monotonic function; necessary and sufficient condition; p-gamma function; p-psi function; Inequality

MSC: Primary 33D05; Secondary 26A48, 33B15, 33E50

 

Author Biography

  • Feng Qi, Department of Mathematics, College of Science, Tianjin Polytechnic University Tianjin City, 300160, China

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How to Cite

Krasniqi, V., & Qi, F. (2014). Complete monotonicity of a function involving the p-psi function and alternative proofs. Global Journal of Mathematical Analysis, 2(3), 204-208. https://doi.org/10.14419/gjma.v2i3.3096

Received date: June 30, 2014

Accepted date: July 26, 2014

Published date: August 3, 2014