How Can I Evaluate This Intriguing Integral in Analytic Number Theory?

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SUMMARY

The integral under discussion is defined as \int_{1}^{\infty}\frac{\left \{x \right \}}{x}\left(\frac{1}{x^{s}-1}\right)dx for \Re(s)>1, where \left \{x \right \} represents the fractional sawtooth function. The user attempted to evaluate it using Fourier expansion but did not achieve a solution. The integral can be manipulated to \frac{1}{2\pi i }\int_{1}^{\infty}\frac{\left(\pi i +\ln(-e^{2\pi i x}) \right )}{x(x^{s}-1)}dx, indicating a potential path forward for evaluation.

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  • Understanding of analytic number theory concepts
  • Familiarity with Fourier series and expansions
  • Knowledge of complex analysis, particularly integrals involving logarithmic functions
  • Proficiency in manipulating integrals and series
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  • Research techniques for evaluating integrals involving the sawtooth function
  • Study the properties of the nome q=e^{i \pi x} in relation to integrals
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Mathematicians, particularly those specializing in analytic number theory, complex analysis, and integral evaluation, will find this discussion beneficial for deepening their understanding of intricate integrals and their properties.

riemannian
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greetings . the following integral appears in some references on analytic number theory . i am really intrigued by it . and would love to understand it .
\int_{1}^{\infty}\frac{\left \{x \right \}}{x}\left(\frac{1}{x^{s}-1}\right)dx

\Re(s)>1 , \left \{x \right \} is the fractional , sawtooth function .

i have tried the Fourier expansion of the sawtooth function :

\int_{1}^{\infty}\frac{\left \{x \right \}}{x}\left(\frac{1}{x^{s}-1}\right)dx = \int_{1}^{\infty}\frac{1}{x(x^{s}-1)}\left(\frac{1}{2}-\frac{1}{\pi}\sum_{n=1}^{\infty}\frac{\sin(2\pi i nx)}{n} \right )dx =\int_{1}^{\infty}\frac{1}{x(x^{s}-1)}\left(\frac{1}{2}+\frac{1}{2\pi i}\ln \left(\frac{1-q^{2}}{1-q^{-2}} \right)\right )dx

where q is the nome :
q=e^{i \pi x}

but that brought me no where near a solution ! any suggestions on how to do the integral ??
 
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after some manipulation , the integral reduces to :

\frac{1}{2\pi i }\int_{1}^{\infty}\frac{\left(\pi i +\ln(-e^{2\pi i x}) \right )}{x(x^{s}-1)}dx
 

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