## Real Analysis Exchange

- Real Anal. Exchange
- Volume 44, Number 1 (2019), 89-100.

### The Inequality of Milne and its Converse, III

Horst Alzer and Alexander Kovačec

#### Abstract

The discrete version of Milne’s inequality and its converse states that \begin{equation*} (*)\quad \sum_{j=1}^n\frac{w_j}{1-p_j^2} \leq \sum_{j=1}^n\frac{w_j}{1-p_j} \sum_{j=1}^n\frac{w_j}{1+p_j} \leq \Bigl(\sum_{j=1}^n\frac{w_j}{1-p_j^2} \Bigr)^2 \end{equation*} is valid for all \(w_j>0\) \((j=1,...,n)\) with \(w_1+\dots+w_n=1\) and \(p_j\in (-1,1)\) \((j=1,...,n)\). We present new upper and lower bounds for the product \(\sum w/(1-p) \sum w/(1+p)\). In particular, we obtain an improvement of the right-hand side of \((*)\). Moreover, we prove a matrix analogue of our double-inequality.

#### Article information

**Source**

Real Anal. Exchange, Volume 44, Number 1 (2019), 89-100.

**Dates**

First available in Project Euclid: 27 June 2019

**Permanent link to this document**

https://projecteuclid.org/euclid.rae/1561622434

**Digital Object Identifier**

doi:10.14321/realanalexch.44.1.0089

**Mathematical Reviews number (MathSciNet)**

MR3951336

**Zentralblatt MATH identifier**

07088965

**Subjects**

Primary: 26D15: Inequalities for sums, series and integrals

Secondary: 15A45: Miscellaneous inequalities involving matrices

**Keywords**

Milne's inequality matrix inequalities

#### Citation

Alzer, Horst; Kovačec, Alexander. The Inequality of Milne and its Converse, III. Real Anal. Exchange 44 (2019), no. 1, 89--100. doi:10.14321/realanalexch.44.1.0089. https://projecteuclid.org/euclid.rae/1561622434