Is there a closed form for the harmonic series?

In summary, the conversation discusses the concept of a closed form for the harmonic series, specifically in relation to Euler's offering of the equation \Sigma1/n= ln(n) + \gamma. It is explained that this equation, while not considered a closed form in the usual sense, can be interpreted as an asymptotic equivalence for large n. The conversation also touches on the inclusion of a "Kth" Bernoulli number in the equation and clarifies that neither an integral nor a sum, finite or infinite, would be considered a closed form for harmonic numbers.
  • #1
avocadogirl
53
0
Taking from Euler's offering that:

[tex]\Sigma[/tex]1/n= ln(n) + [tex]\gamma[/tex]

could you say that there is a closed form of the harmonic series?

Does Euler's offering qualify?
 
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  • #2
Your = is not the usual =, but the asymptomic =. As such it is not a closed form in the usual sense. To talk of a closed form one needs to define which functions and operations are to be acceptable and as in this case in what sense two forms are to be equal. The harmonic series in usually not considered to have a closes form as it can not be written in terms of the usual function with the usual =.
 
  • #3
Could you please explain a little more about this asymptotic equivalence?

Would it be more accurate to include the summation of a "Kth" Bernoulli number, divided by the product of "K" and (n raised to the power of "K"), as K goes from one to infinity?

But, including this summation would not constitute closed form, correct?
 
  • #4
avocadogirl said:
Taking from Euler's offering that:

[tex]\Sigma[/tex]1/n= ln(n) + [tex]\gamma[/tex]]
No, Euler never said any such thing. The equation you write is obviously false. On the left, you have a sum with n varying over some unstated domain so the sum itself does NOT depend on n, but the right hand side does.

could you say that there is a closed form of the harmonic series?

Does Euler's offering qualify?
 
  • #5
avocadogirl said:
Could you please explain a little more about this asymptotic equivalence?

Would it be more accurate to include the summation of a "Kth" Bernoulli number, divided by the product of "K" and (n raised to the power of "K"), as K goes from one to infinity?

But, including this summation would not constitute closed form, correct?

H(n)= ln(n) + Euler–Mascheroni
where Hn is the nth harmonic number
would better be written
H(n)~ln(n) + Euler–Mascheroni
to avoid confusion
interpeted as
limit [-H(n)+ ln(n) + Euler–Mascheroni]=0

That is to say that while the two sides are never equal the get closer the large n gets

and no a integral or a sum (finite or infinite) would not be considered a closed form for harmonic numbers
 
  • #6
Thank you! That clarifies.
 

1. What is the harmonic series?

The harmonic series is a mathematical series that includes the sum of the reciprocal of all positive integers. It is denoted by Hn and can be written as 1 + 1/2 + 1/3 + 1/4 + ... + 1/n.

2. Is there a closed form for the harmonic series?

No, there is no known closed form for the harmonic series. This means that it cannot be expressed as a finite combination of constants, variables, and elementary functions.

3. Why is it difficult to find a closed form for the harmonic series?

The difficulty in finding a closed form for the harmonic series lies in the nature of the series itself. As the series contains an infinite number of terms, it is extremely complex and does not follow any simple patterns or rules.

4. Can the harmonic series be expressed using other mathematical functions?

Yes, the harmonic series can be approximated using various mathematical functions such as logarithms and integrals. However, these approximations are not exact and do not provide a truly closed form for the series.

5. Are there any practical applications of the harmonic series?

While the harmonic series does not have any direct practical applications, it is often used in theoretical mathematics and serves as a fundamental example in the study of series and sequences. It also has connections to other areas of mathematics, such as number theory and calculus.

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