Definition:Riemann Zeta Function/Historical Note

Historical Note on Riemann Zeta Function
The Riemann zeta function was discussed by in his $1859$ article.

In that paper he made several statements about that function.

Studying it led to his proof of the Prime Number Theorem.

All of the statements made in that paper have now been proved except for one.

The last remaining statement which has not been resolved is the Riemann Hypothesis.

When first investigated this function, he used $s$ instead of the more typical complex variable $z$.

To this day, $s = \sigma + i t$ is still typically used as the complex variable in investigations of the zeta function.