# Dirichlet eta function and the Riemann hypothesis

I understand that the following relation exists:

$\eta(s) = \left(1-2^{1-s}\right) \zeta(s)$

and from this question:

What are the hypothetical zeros of the Dirichlet eta function

that the Dirichlet eta function zeros "are precisely the zeros of the zeta function", but then I am confused by this paper:

https://arxiv.org/abs/1201.1810

The author claims to "show that the Dirichlet eta function has no zeros in the critical strip off the critical line, consistent with the Riemann hypothesis."

My question is how is this only consistent with the Riemann hypothesis, or in other words, how does this result not imply the Riemann hypothesis?

• It is consistent in that it proves any zeros in the critical strip must be on the critical line...which is not contradictory to the Riemann hypothesis. – Simply Beautiful Art Apr 20 '17 at 0:29
• @SimplyBeautifulArt Yes, I see how it is consistent. I am confused how it is not also sufficient to prove the Riemann hypothesis. – nellapizza Apr 20 '17 at 1:04
• Note that it does not prove that there cannot be zeros outside of the critical strip, with the exception of the negative even integers. – Simply Beautiful Art Apr 20 '17 at 1:08
• @SimplyBeautifulArt But then from Wolfram MathWorld : "All nontrivial zeros (i.e., those not at negative even integers) of the Riemann zeta function lie inside this strip." Since Dirichlet eta function zeros and Riemann zeta function zeros are the same inside the critical strip and all Dirichlet eta function zeros inside the strip are on the critical line doesn't that imply that all Riemann zeta function zeros are on the critical line as well. – nellapizza Apr 20 '17 at 1:22
• @nellapizza, you are correct that this result implies the Riemann hypothesis. The paper itself is junk. – Peter Humphries Apr 20 '17 at 5:29

The zeroes of $\zeta(s)$ within the critical strip are precisely the same zeroes as of $\eta(s)$ within the critical strip. However, the paper you reference is junk.