# The zeta function has infinitely many zeros in $0<\Re{s}<1/2$?

The following paragraph appears on page 42 in the book Rational Number Theory in the 20th Century: From PNT to FLT (Par Wladyslaw Narkiewicz):

The fact that the strip $0<\Re{s}<1/2$ contains infinitely many zeros of the zeta-function follows from the formula for the number of zeros lying in the rectangle $0<\Re{s}<1/2$, $0<\Im{s}<T$, conjectured by Riemann and established by H. von Mangoldt in 1895: $$N(T)=\frac{1}{2\pi}T\log\left(\frac{T}{2\pi}\right)-\frac{T}{2\pi}+R(T)$$ with $R(T)=O(\log^2T)$.

Wouldn't this contradict the Riemann hypothesis?

• Looking at some other sources, it appears that to be a typo: It should be "$0<\Re s<1$" not "$0<\Re s <1/2"$, i.e. the number of zeros in the critical strip. – Semiclassical Dec 24 '16 at 18:09
• I've voted to reopen, since the OP is right, this is a (very unfortunate) typo. – Noah Schweber Dec 24 '16 at 18:33
• The typo could be too $0<\Re{s}<1/2$ instead of $\,0<\Re{s}\le 1/2\,$ since any zero in $1/2<\Re{s}<1$ would have a counterpart in $0<\Re{s}<1/2$ from the functional equation. – Raymond Manzoni Dec 25 '16 at 10:48

Looking at some other sources, it appears that to be a typo: It should be "$0<\Re s<1$" not "$0<\Re s<1/2$", i.e. the number of zeros in the critical strip.
In fact, no non-trivial zeros of the Riemann Zeta function occur outside the critical strip, so this restriction is superfluous i.e. the formula gives the number of zeroes in $0 <\Im s<T$. It is in this form that Wikipedia and Mathworld state the Riemann-von Mangoldt formula. Technical sources can be found in both links.
Yes, if it were correct, the Riemann hypothesis would be false. It's definitely a typo, however. You can see, for example, here for a fairly detailed proof; suffice to say that nothing can be done to cut the region of validity down effectively, due to the difficult nature of the $\zeta$-function's behaviour in the critical strip.