Abstract
In the article the authors present necessary and sufficient conditions for a function involving the logarithm of the gamma function to be completely monotonic and apply these results to bound the gamma function \(\Gamma (x)\), the \(n\)-th harmonic number \(\sum _{k=1}^n\frac{1}{k}\), and the factorial \(n!\).
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Acknowledgments
The authors would like to express many thanks to the anonymous referee for his/her careful comments on and accurate corrections to the original version of this paper. The present investigation was supported in part by the Natural Science Foundation Project of Chongqing, China under Grant CSTC2011JJA00024, the Research Project of Science and Technology of Chongqing Education Commission, China under Grant KJ120625, and the Fund of Chongqing Normal University, China under Grant 10XLR017 and 2011XLZ07
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Qi, F., Luo, QM. Complete monotonicity of a function involving the gamma function and applications. Period Math Hung 69, 159–169 (2014). https://doi.org/10.1007/s10998-014-0056-x
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DOI: https://doi.org/10.1007/s10998-014-0056-x
Keywords
- Complete monotonicity
- Logarithmically completely monotonic function
- Gamma function
- Inequality
- Necessary and sufficient condition
- Harmonic number
- Factorial
- Application