Integral moment of the Riemann zeta function and Hecke $L$ functions
Zhaoyan Chen
TL;DR
The article establishes asymptotic formulas for mixed moments of the Riemann zeta function and a Hecke $L$-function attached to a Hecke cusp form on the critical line, including a result for the product with $|ζ|^{2}$. The approach hinges on exact approximate functional equations, careful analysis of Dirichlet-series sums, and stationary-phase methods to handle oscillatory integrals, yielding a main term of the form $\frac{c}{2} L(1,f) T \log T + c_f T$ with a power-saving error. The work extends classical moment results to the joint setting with automorphic $L$-functions and derives short-interval corollaries by leveraging known moment bounds and smoothing arguments. This provides precise mean-value information for mixed zeta–$L$-function moments, with implications for understanding correlations between $ζ(s)$ and automorphic $L$-functions. The results unify analytic techniques for moments, approximate functional equations, and oscillatory integral estimates in the $GL(2)$ automorphic setting.
Abstract
Let $f$ be a Hecke cusp form for $SL(2,\mathbb{Z})$. We prove an asymptotic formula for the mixed moment of the product of $ζ(s)$ and $L(s,f)$ on the critical line. Similarly, we prove an asymptotic formula for the mixed moment of the product of $|ζ^{2}(s)|$ and $L(s,f)$ on the critical line.
