The discrete second moment of mixed derivatives of the Riemann zeta function
Benjamin Durkan, Christopher Hughes, Andrew Pearce-Crump
TL;DR
This paper establishes a full asymptotic expansion, with power-saving or RH-conditional errors, for the discrete second moment $\sum_{0<\gamma\le T}\zeta^{(\mu)}(\rho)\zeta^{(\nu)}(1-\rho)$ of mixed derivatives of the Riemann zeta function. The authors develop a contour-integral framework, decompose the right- and left-hand vertical segments via functional equations into convergent Dirichlet series, and extract the main term as a polynomial $\mathcal{P}_{\mu,\nu}(x)$ in $\log(T/2\pi)$ by residues at $s=1$ with coefficients tied to Laurent expansions around $s=1$. Under RH they obtain $O(T^{1/2+\varepsilon})$ error; unconditionally the error is $O(T e^{-C\sqrt{\log T}})$. The results generalize prior work (Gonek, Conrey--Snaith, Milinovich) to all derivatives, recover Milinovich4s polynomial for $\mu=\nu=1$, and yield corollaries for higher derivatives and related mixed moments, with explicit coefficient data in terms of Laurent constants. This advances precise moment calculations in analytic number theory and informs conjectures about zeta-derivative statistics at zeros.
Abstract
We establish the full asymptotic for the discrete second moment of the Riemann zeta function of mixed derivatives evaluated at the zeta zeros, providing both unconditional and conditional error terms. This was first studied by Gonek, where only the leading order asymptotic was given, later extended by Conrey--Snaith and Milinovich to include the lower order terms for the first derivative. We extend the case of the first derivative to all derivatives.
