scholarly journals Optimal Lower Power Mean Bound for the Convex Combination of Harmonic and Logarithmic Means

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Ming Chu ◽  
Shan-Shan Wang ◽  
Cheng Zong

We find the least valueλ∈(0,1)and the greatest valuep=p(α)such thatαH(a,b)+(1−α)L(a,b)>Mp(a,b)forα∈[λ,1)and alla,b>0witha≠b, whereH(a,b),L(a,b), andMp(a,b)are the harmonic, logarithmic, andp-th power means of two positive numbersaandb, respectively.

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Wei-Feng Xia ◽  
Yu-Ming Chu ◽  
Gen-Di Wang

Forp∈ℝ, the power meanMp(a,b)of orderp, logarithmic meanL(a,b), and arithmetic meanA(a,b)of two positive real valuesaandbare defined byMp(a,b)=((ap+bp)/2)1/p, forp≠0andMp(a,b)=ab, forp=0,L(a,b)=(b-a)/(log⁡b-log⁡a), fora≠bandL(a,b)=a, fora=bandA(a,b)=(a+b)/2, respectively. In this paper, we answer the question: forα∈(0,1), what are the greatest valuepand the least valueq, such that the double inequalityMp(a,b)≤αA(a,b)+(1-α)L(a,b)≤Mq(a,b)holds for alla,b>0?


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Yong-Min Li ◽  
Bo-Yong Long ◽  
Yu-Ming Chu ◽  
Wei-Ming Gong

We present the best possible power mean bounds for the productMpα(a,b)M-p1-α(a,b)for anyp>0,α∈(0,1), and alla,b>0witha≠b. Here,Mp(a,b)is thepth power mean of two positive numbersaandb.


2020 ◽  
pp. 1-18 ◽  
Author(s):  
MOHSEN KIAN ◽  
MOHAMMAD SAL MOSLEHIAN ◽  
YUKI SEO

Abstract For an n-tuple of positive invertible operators on a Hilbert space, we present some variants of Ando–Hiai type inequalities for deformed means from an n-variable operator mean by an operator mean, which is related to the information monotonicity of a certain unital positive linear map. As an application, we investigate the monotonicity of the power mean from the deformed mean in terms of the generalized Kantorovich constants under the operator order. Moreover, we improve the norm inequality for the operator power means related to the Log-Euclidean mean in terms of the Specht ratio.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Hongya Gao ◽  
Jianling Guo ◽  
Wanguo Yu

For1<r<+∞, we find the least valueαand the greatest valueβsuch that the inequalityHα(a,b)<Ar(a,b)<Hβ(a,b)holds for alla,b>0witha≠b. Here,Hω(a,b)andAr(a,b)are the generalized Heronian and the power means of two positive numbersaandb, respectively.


2004 ◽  
Vol 2004 (1) ◽  
pp. 49-53
Author(s):  
Feng Qi ◽  
Bai-Ni Guo ◽  
Lokenath Debnath

Letnandmbe natural numbers. Suppose that{ai}i=1n+mis an increasing, logarithmically convex, and positive sequence. Denote the power meanPn(r)for any given positive real numberrbyPn(r)=((1/n)∑i=1nair)1/r. ThenPn(r)/Pn+m(r)≥an/an+m. The lower bound is the best possible.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yu-Ming Chu ◽  
Bo-Yong Long
Keyword(s):  

In this paper we find the best possible lower power mean bounds for the Neuman-Sándor mean and present the sharp bounds for the ratio of the Neuman-Sándor and identric means.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Yu-Ming Chu ◽  
Zhen-Hang Yang ◽  
Li-Min Wu

We prove that the double inequalityMp(a,b)<X(a,b)<Mq(a,b)holds for alla,b>0witha≠bif and only ifp≤1/3andq≥log 2/(1+log 2)=0.4093…, whereX(a,b)andMr(a,b)are the Sándor andrth power means ofaandb, respectively.


2012 ◽  
Vol 2012 ◽  
pp. 1-14
Author(s):  
Wei-Mao Qian ◽  
Zhong-Hua Shen

We prove thatαH(a,b)+(1−α)L(a,b)>M(1−4α)/3(a,b)forα∈(0,1)and alla,b>0witha≠bif and only ifα∈[1/4,1)andαH(a,b)+(1−α)L(a,b)<M(1−4α)/3(a,b)if and only ifα∈(0,3345/80−11/16), and the parameter(1−4α)/3is the best possible in either case. Here,H(a,b)=2ab/(a+b),L(a,b)=(a−b)/(log a−log b), andMp(a,b)=((ap+bp)/2)1/p(p≠0)andM0(a,b)=abare the harmonic, logarithmic, andpth power means ofaandb, respectively.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xiaoxue Li ◽  
Li Chen

The main purpose of this article is using the analytic methods and the properties of the classical Gauss sums to study the calculating problem of the hybrid power mean of the two-term exponential sums and quartic Gauss sums and then prove two interesting linear recurrence formulas. As applications, some asymptotic formulas are obtained.


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