There has been a paper doing rounds on Facebook for the past several days, claiming a proof of the Riemann hypothesis. I feel sure that the argument is flawed, but can't see where exactly. It goes as follows:
Let $\pi(x)$ be the number of primes not exceeding $x$ and $Li(x) = \int_{1}^{x} \frac{dt}{\log t}$. Consider the prime zeta function
$$\sum_{p} p^{-s} = \sum_{m=1}^{\infty} \frac{\mu(m)}{m}\log \zeta(ms)$$ for $\Re(s)=\sigma>1$, where $\mu$ and $\zeta$ denote the Mobius and Riemann zeta functions, respectively.
Applying partial summation to the left-hand side sum over primes $p$ together with the identity $\int_{1}^{\infty} s Li(x)x^{-s-1} \mathrm{d}x=-\log(s-1)$ for $\sigma>1$ yields
$$s\int_{1}^{\infty} (\pi(x)-Li(x))x^{-s-1} \mathrm{d}x-\log((s-1)\zeta(s))=\sum_{m=2}^{\infty} \frac{\mu(m)}{m}\log \zeta(ms)$$ for $\sigma>1$, where $\Theta\leq 1$ denotes the supremum of the real parts of the zeros of $\zeta$. The integral on the left-hand side shall be referred to as $F (s)$ forthwith.
We know that $|π(x) − Li(x)| \ll x ^{\Theta} \log x$ and $\Theta$ is the abscissa of convergence of $F (s)$ (Theorem 1.3 of Montgomery-Vaughan). Thus the domain of the above equation extends by analytic continuation to the half-plane $H = \lbrace s : σ > Θ \rbrace.$
Notice that the right-hand side of the above equation converges whenever $σ > 1/2$ since $|μ(m) \log ζ(ms)| \ll 2^{ −mσ}$ for all $m ≥ 2$ and $σ > 1/2.$ Thus we arrive at $Θ ≤ 1/2$, which proves the Riemann hypothesis ?
If we care of $Li(x)=1_{x>2}\int_2^x\frac{dt}{\log t}$ it is because its Mellin transform is $$L(s)= \int_2^\infty Li(x)x^{-s-1}dx= \int_2^\infty \frac1{\log x}\frac{x^{-s}}{s}dx=\frac1s (2Li(2)-\int_2^s\int_2^\infty x^{-z}dxdz)$$$$=\frac1s(2Li(2)-\int_2^s \frac{2^{1-z}}{z-1}dz)=\frac{F(s)}{s}-\frac{\log (s-1)}{s}$$
where $F(s)=2Li(2)-\int_2^s \frac{2^{1-z}-1}{z-1}dz$ is entire. With $P(s)=\sum_p p^{-s}$
$$\frac{P(s)}{s}+\frac{\log(s-1)}{s}=\int_0^{\infty} (\pi(x)-Li(x))x^{-s-1} \mathrm{d}x+\frac{F(s)}{s} $$
and
$$s\int_0^{\infty} (\pi(x)-Li(x))x^{-s-1} \mathrm{d}x-\log\zeta(s)-\log(s-1)=-F(s) -\sum_{p^k,k\ge 2}\frac{p^{-sk}}{k}$$
So this doesn't tell anything of the Riemann hypothesis.