How to Derive the Exact Expression for Dirichlet Series g(s)?

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Discussion Overview

The discussion centers on deriving the exact expression for the Dirichlet series g(s) defined as g(s) = ∑_{1 ≤ n} |Λ(n)|² n^{-s}, where Λ is the von Mangoldt function. Participants explore methods for obtaining this expression and the Mellin transform of the product Λ(n+2)Λ(n), including attempts at using properties of Dirichlet series and partial summation techniques.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant presents the series g(s) and asks for methods to derive an exact or approximate expression for it.
  • Another participant discusses the property of Dirichlet series and questions the applicability of a certain transformation involving g(s) and its derivative, suggesting it may not work unless f(n) is multiplicative.
  • A later reply references a result from Tom Apostol's book, relating the desired series to an integral involving the derivative of the Riemann zeta function, but expresses uncertainty about the value of the integral.
  • Another participant shares their attempt using partial summation to relate g(s) to a function B(x), seeking hints for further progress.

Areas of Agreement / Disagreement

Participants do not appear to reach consensus on the methods for deriving g(s) or the value of the integral mentioned. Multiple approaches and ideas are presented, indicating ongoing exploration and uncertainty.

Contextual Notes

Some methods discussed depend on specific properties of functions and may require assumptions about multiplicativity. The integral's value remains unresolved, and the applicability of certain transformations is questioned.

mitchell2007
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Let be the series in the form [tex]g(s)= \sum_{1 \le n } |\Lambda (n) |^{2} n^{-s}[/tex] where lambda is Von Mangoldt function, my question is how could i get an exact or at least almost exact expresion for g(s) . My other question is how could i obtainthe Mellin transform of the function [tex]\Lambda (n+2) \Lambda (n+1)[/tex] i have tried sum by parts but got no results.
 
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of course i tried (wrong ??) with the property, given a Dirchlet series [tex]g(s)= \sum_{1 \le n} f(n)n^{-s}[/tex] then [tex]-g'(s)/g(s)= \sum_{1 \le n} f(n) \Lambda (n) n^{-s}[/tex] but i think this does not work unless f(n) is multiplicative, however could it be used at least as a good approximation or modifying it a bit coul work??
 
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Welcome back, Jose.
 
readng Tom Apostol's 'Introduction to Analytic number theory' the desired series is just [tex]AT^{-1} \int_{-T}^{T}dt | \frac{ \zeta ' (a+it)}{\zeta (a+it)} |^{2} = \sum_{1 \le n} | \Lambda (n) |^{2} n^{2a}[/tex] , with a>1 and T tending to infinity. but i don't know the value of the integral, could someone provide an approximate value of the integral over t (-T,T) above ??, thank you.
 
How many accounts has this guy made on here?
 
I have also tried using partial summation so:

[tex]\sum_{n \le x } \Lambda (n+2) \Lambda (n) = B(x)= \Lambda (x+2) \Psi (x) - \sum_{n \le x } \Psi (x) ( \Lambda (x+2) - \Lambda (x+1) )[/tex]

so [tex]g(s)= \sum_{1 \le n} \Lambda (n+2) \Lambda (n) n^{-s}= s \int_{1}^{\infty}B(x) x^{- (s+1)}[/tex]

to obtain 'g(s)' any hint please?? thanx.
 

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