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Define $\theta(x)=\sum_{p\leq x} \log p $, where $p>1$ denotes a prime. Nicolas proved that if the Riemann zeta function $\zeta(s)$ vanishes for some $s$ with $\Re(s)\leq 1/2 + b$, where $b\in(0, 1/2)$, then

$$\log\Big(e^{\gamma}(\log \theta(x))\prod_{p\leq x} (1-p^{-1})\Big)=\Omega_{\pm }(x^{-b}).$$

Is the reverse necessarily true ? It appears so to me, since

$$\theta(x)=x +O(\sqrt{x})-\sum_{\rho} \frac{x^{\rho}}{\rho},$$

where the sum is over the complex zeros of $\zeta$ and $\prod_{p\leq x} (1-p^{-1})\sim e^{-\gamma}(\log x)^{-1} ?$

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  • $\begingroup$ Do you have a reference? $\endgroup$ – András Bátkai Mar 10 at 18:41
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    $\begingroup$ @AndrásBátkai Nicolas puts most of his stuff on his site. math.univ-lyon1.fr/~nicolas and publications at math.univ-lyon1.fr/~nicolas/publications.html $\endgroup$ – Will Jagy Mar 10 at 22:31
  • $\begingroup$ @WillJagy: thanks, I also found this. I meant a bit more precise reference for the result recalled above. $\endgroup$ – András Bátkai Mar 11 at 8:07
  • $\begingroup$ @AndrásBátkai, I see what you mean. Maybe the OP will loh at th Nicolas page and indicate which publication is relevant $\endgroup$ – Will Jagy Mar 11 at 17:06
  • $\begingroup$ The explicit formula doesn't help a lot because it doesn't converge absolutely. Under the RH $\theta(x) = x+O(\sqrt{x} \log^2x)$ you can't improve it much. It is easy to show if $\theta(x)-x = o(x^{\sigma})$ then $\zeta(s)$ has no zeros for $\Re(s) \ge \sigma$, the converse is much harder $\endgroup$ – reuns Mar 11 at 21:08
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The result Nicolas proved (Theorem 3, Jean-Louis Nicolas. Petites valeurs de la fonction d'Euler, J. Number Theory, 17, 1983, 375--388, paper linked HERE) is actually not quite what is claimed in this post, but:

$\log\Big(e^{\gamma}(\log \theta(x))\prod_{p\leq x} (1-p^{-1})\Big)=\Omega_{\pm }(x^{b-\frac{1}{2}-\epsilon})$, for all $\epsilon > 0$, where $0< b < \frac{1}{2}$ is such that RZ has a zero with real part $\frac{1}{2} + b$, so it is in the classical spirit as the worse RH fails (the higher the supremum of the real part of the critical zeros), the stronger the claimed $\Omega$.

The estimate claimed in the post above is wrong (obviously because it is stronger for a weaker claim, not to speak that since RZ always vanishes on the critical line the claim of the post would imply the estimate to be true for $b$ going to zero and that contradicts the later claim when RZ is true). Using the zeros symmetry around the critical line, one can rephrase the $\Omega$ result to:

$\log\Big(e^{\gamma}(\log \theta(x))\prod_{p\leq x} (1-p^{-1})\Big)=\Omega_{\pm }(x^{-\beta-\epsilon})$, for all $\epsilon > 0$, where $0< \beta < \frac{1}{2}$ is such that RZ has a zero with real part $\beta$

He also proved that if RH is true $\log\Big(e^{\gamma}(\log \theta(x))\prod_{p\leq x} (1-p^{-1})\Big)x^{\frac{1}{2}}\log x$ is always negative for $x>2$, has inferior limit $\log{4\pi}-4-\gamma$ and superior limit less or equal to $\gamma - \log{4\pi}$ which are both close to $-2$, so obviously any $\Omega$ result as above with a power $x^{-\beta}, 0 < \beta < \frac{1}{2}$ dispproves RH, with the lower the $\beta$ the worse RH fails, while any $O$ result gives bounds on the supremum of the real parts of critical zeros, with the higher the $\beta$ the better the bounds

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  • $\begingroup$ You claim in the MSE post that the inequality is reversed and the PNT corresponds to $\beta=0$. Both of these claims are clearly false because 1.) The inequality sign is clearly ''>'' not otherwise, and you can find this everywhere in the literature, e.g Lagarias ''An elementary problem equivalent to the RH''. 2.) The PNT certainly doesn't correspond to $\beta=0$, because the PNT is the statement that $\zeta(s)\neq 0$ for $\Re(s)=1/2 + \beta =1$. $\endgroup$ – ABD. Apr 29 at 18:19
  • $\begingroup$ Actually, the fact that the inequality is false for $\beta=0$ is independent of the PNT. It is indeed an immediate consequence of Gronwall's classical result that $\lim sup_{n\rightarrow \infty} \frac{\sigma(n)}{n\log \log n} =e^{\gamma}$. $\endgroup$ – ABD. Apr 29 at 18:43
  • $\begingroup$ The mse post is a fallacy and it is based on a complete misinterpretation of Robin results. Robin proved 3 things, equivalence to RH, unconditional result that shows an O result and what happens when there are zeros with real part in $(.5,1)$ and in that case there is an omega results that gets more powerful, the higher the real parts of zeros get. The fact that there are no zeros at 1 has no relevance there, but it can be interpreted - not proved per se, just INTERPRETED to confirm that the powerful omega result cannot hold at zero, so the statement on mse $\endgroup$ – Conrad Apr 29 at 21:37
  • $\begingroup$ see www.2874565.com/q/329837/83236. Quite stranger that you've now diverted from your first comments on the subject. $\endgroup$ – ABD. Apr 29 at 21:45
  • $\begingroup$ We seem to go in circles - as I noted in other posts on this theme, you ain't going to convince me that false is true whatever rhetoric or sophistry you use; the papers of Robin and Nicolas are quite clear and I looked them up earlier today to confirm details like theorem number and page to avoid misrepresentations like the one above regarding PNT; your post on mse, comments here etc are fallacies and they seem to be in a malicious intentional spirit not in an honest mistake one and as noted it is pointless to keep explaining your fallacy, but feel free to go ahead and publish your results $\endgroup$ – Conrad Apr 29 at 22:03
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Actually, in the paper cited in answer one, the following is proved:

$\log (e^\gamma\log(\theta(x))\prod_{p\le x}(1-1/p))<0$ for $x\ge 3$ if and only if the Riemann Hypothesis holds ... I don't know how to link to other posts, but essentially this same question is asked again (this one came first).

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  • $\begingroup$ i think it's because the result seems to have some highly non-trivial implications, see www.2874565.com/q/330258/83236 $\endgroup$ – ABD. Apr 29 at 6:52
  • $\begingroup$ The link you provide is not available any more. $\endgroup$ – EGME Apr 29 at 11:31
  • $\begingroup$ In the post www.2874565.com/q/329837/83236 it seems you agreed that $a\in(1/2, 1]$ is the supremum of the real parts of the zeros of $\zeta$ if and only if $f(x)=\Omega_{\pm}(x^{-b})$, Notice that if the inequality concerned is false for some $b$, then it is also false for any $b'<b$. Thus since $a\in(1/2, 1]$ is the supremum of the real parts of the zeros of $\zeta$ if and only if $f(x)=\Omega_{\pm}(x^{-b})$, it follows that the inequality is false for $\beta=1/2$ since $\zeta(s)\neq 0$ for $\Re(s)=1/2+\beta\geq 1$, hence $\zeta(s)\neq 0$ for $\Re(s)>1/2$. $\endgroup$ – ABD. Apr 29 at 18:35
  • $\begingroup$ ...where $b$ can be taken to have any value in $(a-1/2, 1/2]$. $\endgroup$ – ABD. Apr 29 at 18:46
  • $\begingroup$ $ABD: Ok, I see the post again, strange. If $a>1/2$ the $f$ oscillates (proved in theorem 3, more specifically, for all $b$ between $1-a$ and $1/2$, $f(x)=\Omega_{\pm}(x^{-b})$), and if $f$ oscillates, then $a>1/2$ (this much follows). Hmm, now I am not sure which inequality you are referring to which may be false for some $b$, maybe this is better discussed in that post, I can’t see two posts at the same time on my device. I hope I have no typos, I can’t see the latex in comments. $\endgroup$ – EGME Apr 29 at 19:48

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