Complete monotonicity of some functions involving polygamma functions |
| |
Authors: | Feng Qi Senlin Guo Bai-Ni Guo |
| |
Institution: | a Department of Mathematics, College of Science, Tianjin Polytechnic University, Tianjin City, 300160, China b Department of Mathematics, Zhongyuan University of Technology, Zhengzhou City, Henan Province, 450007, China |
| |
Abstract: | In the present paper, we establish necessary and sufficient conditions for the functions xα|ψ(i)(x+β)| and α|ψ(i)(x+β)|−x|ψ(i+1)(x+β)| respectively to be monotonic and completely monotonic on (0,∞), where i∈N, α>0 and β≥0 are scalars, and ψ(i)(x) are polygamma functions. |
| |
Keywords: | 26A48 26A51 26D20 33B10 33B15 44A10 |
本文献已被 ScienceDirect 等数据库收录! |
|