Sum of Reciprocals of Powers as Euler Product/Corollary 1/Examples/Zeta(2) over Zeta(4)

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Example of Use of Sum of Reciprocals of Powers as Euler Product/Corollary 1

$\ds \prod_{\text {$p$ prime} } \paren {1 + p^{-2} } = \dfrac {15 } {\pi^2}$

where the infinite product runs over the prime numbers.


Proof

\(\ds \prod_{\text {$p$ prime} } \paren {1 + p^{-s} }\) \(=\) \(\ds \dfrac {\map \zeta s} {\map \zeta {2 s} }\) Sum of Reciprocals of Powers as Euler Product/Corollary 1
\(\ds \leadsto \ \ \) \(\ds \prod_{\text {$p$ prime} } \paren {1 + p^{-2} }\) \(=\) \(\ds \dfrac {\map \zeta 2} {\map \zeta 4}\)
\(\ds \) \(=\) \(\ds \dfrac {\dfrac {\pi^2} 6} {\dfrac {\pi^4} {90} }\) Basel Problem and Riemann Zeta Function of 4
\(\ds \) \(=\) \(\ds \dfrac {90} {6 \pi^2}\)
\(\ds \) \(=\) \(\ds \dfrac {15} {\pi^2}\)

$\blacksquare$