Summing Infinite Series with Dilogarithms

In summary, the conversation discusses a challenging problem involving the sum of fractions and its connection to an intriguing integral. The problem is proven to equal 11π^4/360 using an approach involving Dilogarithms. A paper by Borwein & Borwein is also mentioned as a reference for further reading.
  • #1
sbhatnagar
87
0
Hi everyone ;)

I have a challenging problem which I would like to share with you.

Prove that

\[\frac{1}{2^2}+ \frac{1}{3^2} \left(1+\frac{1}{2} \right)^2+\frac{1}{4^2} \left( 1+\frac{1}{2} +\frac{1}{3}\right)^2 + \frac{1}{5^2} \left( 1+\frac{1}{2} +\frac{1}{3}+\frac{1}{4}\right)^2 +\cdots= \frac{11\pi^4}{360}\]
 
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  • #2
sbhatnagar said:
Hi everyone ;)

I have a challenging problem which I would like to share with you.

Prove that

\[\frac{1}{2^2}+ \frac{1}{3^2} \left(1+\frac{1}{2} \right)^2+\frac{1}{4^2} \left( 1+\frac{1}{2} +\frac{1}{3}\right)^2 + \frac{1}{5^2} \left( 1+\frac{1}{2} +\frac{1}{3}+\frac{1}{4}\right)^2 +\cdots= \frac{11\pi^4}{360}\]

The evaluation of...

$$S= \sum_{n=1}^{\infty} \frac{H_{n}^{2}}{(n+1)^{2}} = \frac{11}{360}\ \pi^{4}\ (1)$$

... as well as many other 'Euler's sums' has been performed using an 'intriguing integral' by Borwein & Borwein [;)] in... http://www.math.uwo.ca/~dborwein/cv/zeta4.pdf

Kind regards

$\chi$ $\sigma$
 
  • #3
Thank you chisigma for that nice paper. :D My solution was different from the one given in it.

I used Dilogarithms to evaluate it.
 

FAQ: Summing Infinite Series with Dilogarithms

What is an infinite series?

An infinite series is a mathematical expression that represents the sum of an infinite number of terms. It is denoted by the symbol Σ (sigma) and can be written as a1 + a2 + a3 + ... + an + ... where a1, a2, a3, ... are the individual terms of the series.

How do you evaluate an infinite series?

To evaluate an infinite series, you can use various techniques such as the limit comparison test, ratio test, or integral test. These methods involve determining whether the series converges (approaches a finite value) or diverges (approaches infinity).

What is the difference between a convergent and divergent series?

A convergent series is one that approaches a finite value as the number of terms increases, whereas a divergent series is one that approaches infinity or does not have a limit. In other words, a convergent series has a finite sum, while a divergent series does not.

Can an infinite series have a negative sum?

Yes, an infinite series can have a negative sum if the individual terms of the series alternate between positive and negative values. This is known as an alternating series. However, the sum will still approach a finite value as the number of terms increases.

What are some real-world applications of infinite series?

Infinite series have many applications in fields such as physics, engineering, and finance. For example, they can be used to model the behavior of electrical circuits, estimate the value of complex integrals, and calculate the future value of an investment with compound interest.

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