Logarithmically Complete Monotonicity Properties Relating to the Gamma Function

We prove that the function fα,β(x)=Γβ(x+α)/xαΓ(βx) is strictly logarithmically completely monotonic on (0,∞) if (α,β)∈{( α,β):1/α≤β≤1, α≠1}∪{(α,β):0<β≤1,φ1(α,β)≥0,φ2(α,β)≥0} and [fα,β(x)]-1 is strictly logarithmically completely monotonic on (0,∞) if (α,β)∈{(α,β):0<α≤1/2,0<β≤1}∪{(α,β):1≤β≤1...

Full description

Saved in:
Bibliographic Details
Main Authors: Tie-Hong Zhao, Yu-Ming Chu, Hua Wang
Format: Article
Language:English
Published: Wiley 2011-01-01
Series:Abstract and Applied Analysis
Online Access:http://dx.doi.org/10.1155/2011/896483
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832564070176260096
author Tie-Hong Zhao
Yu-Ming Chu
Hua Wang
author_facet Tie-Hong Zhao
Yu-Ming Chu
Hua Wang
author_sort Tie-Hong Zhao
collection DOAJ
description We prove that the function fα,β(x)=Γβ(x+α)/xαΓ(βx) is strictly logarithmically completely monotonic on (0,∞) if (α,β)∈{( α,β):1/α≤β≤1, α≠1}∪{(α,β):0<β≤1,φ1(α,β)≥0,φ2(α,β)≥0} and [fα,β(x)]-1 is strictly logarithmically completely monotonic on (0,∞) if (α,β)∈{(α,β):0<α≤1/2,0<β≤1}∪{(α,β):1≤β≤1/α≤2,α≠1}∪{(α,β):1/2≤α<1,β≥1/(1-α)}, where φ1(α,β)=(α2+α-1)β2+(2α2-3α+1)β-α and φ2(α,β)=(α-1)β2+(2α2-5α+2)β-1.
format Article
id doaj-art-97fae93df1dc4fd9a7b46a54747b4b36
institution Kabale University
issn 1085-3375
1687-0409
language English
publishDate 2011-01-01
publisher Wiley
record_format Article
series Abstract and Applied Analysis
spelling doaj-art-97fae93df1dc4fd9a7b46a54747b4b362025-02-03T01:11:58ZengWileyAbstract and Applied Analysis1085-33751687-04092011-01-01201110.1155/2011/896483896483Logarithmically Complete Monotonicity Properties Relating to the Gamma FunctionTie-Hong Zhao0Yu-Ming Chu1Hua Wang2Department of Mathematics, Huzhou Teachers College, Huzhou 313000, ChinaDepartment of Mathematics, Huzhou Teachers College, Huzhou 313000, ChinaDepartment of Mathematics, Changsha University of Science and Technology, Changsha 410076, ChinaWe prove that the function fα,β(x)=Γβ(x+α)/xαΓ(βx) is strictly logarithmically completely monotonic on (0,∞) if (α,β)∈{( α,β):1/α≤β≤1, α≠1}∪{(α,β):0<β≤1,φ1(α,β)≥0,φ2(α,β)≥0} and [fα,β(x)]-1 is strictly logarithmically completely monotonic on (0,∞) if (α,β)∈{(α,β):0<α≤1/2,0<β≤1}∪{(α,β):1≤β≤1/α≤2,α≠1}∪{(α,β):1/2≤α<1,β≥1/(1-α)}, where φ1(α,β)=(α2+α-1)β2+(2α2-3α+1)β-α and φ2(α,β)=(α-1)β2+(2α2-5α+2)β-1.http://dx.doi.org/10.1155/2011/896483
spellingShingle Tie-Hong Zhao
Yu-Ming Chu
Hua Wang
Logarithmically Complete Monotonicity Properties Relating to the Gamma Function
Abstract and Applied Analysis
title Logarithmically Complete Monotonicity Properties Relating to the Gamma Function
title_full Logarithmically Complete Monotonicity Properties Relating to the Gamma Function
title_fullStr Logarithmically Complete Monotonicity Properties Relating to the Gamma Function
title_full_unstemmed Logarithmically Complete Monotonicity Properties Relating to the Gamma Function
title_short Logarithmically Complete Monotonicity Properties Relating to the Gamma Function
title_sort logarithmically complete monotonicity properties relating to the gamma function
url http://dx.doi.org/10.1155/2011/896483
work_keys_str_mv AT tiehongzhao logarithmicallycompletemonotonicitypropertiesrelatingtothegammafunction
AT yumingchu logarithmicallycompletemonotonicitypropertiesrelatingtothegammafunction
AT huawang logarithmicallycompletemonotonicitypropertiesrelatingtothegammafunction