Local partial-fraction expansion of the Riemann zeta logarithmic derivative
= Local partial-fraction expansion of the Riemann zeta logarithmic derivative
{c}
Uniformly in a fixed bounded-width disk around height $t$,
$$
\frac{\zeta'(s)}{\zeta(s)}
=\sum_{\rho\text{ nearby}}\frac1{s-\rho}
+O(\log(|t|+3)).
$$
This follows by taking the logarithmic derivative of the Hadamard product for the completed zeta function and estimating the distant zeros.