Multiplicity of nontrivial zeros of primitive L-functions via higher-level correlations
Felipe Gonçalves, David de Laat, Nando Leijenhorst
TL;DR
This work bounds the fraction of nontrivial zeros of $L(s,\pi)$ with prescribed multiplicity for irreducible cuspidal automorphic representations $\pi$ of $\mathrm{GL}_m/\mathbb{Q}$ by exploiting the $n$-level correlations of zeros via Hejhal and Rudnick–Sarnak, together with semidefinite programming. The authors derive an optimization framework where the asymptotic ratio $\liminf_{T\to\infty} \frac{Z_n(T)}{N(T)}$ is bounded below by $1 - \frac{c_{n,m}}{(n-1)!}$, with $c_{n,m}$ obtained from a kernel- and reproducing-kernel-based SDP. They provide an analytic solution for $n=2$ yielding an explicit bound, and develop polynomial- and shift-based parametrizations to compute bounds for larger $n$ (notably $(n,m)=(3,1)$, $(3,2)$, and $(4,1)$). The results deliver new universal lower bounds on the multiplicity distribution of zeros, demonstrating a scalable framework that blends harmonic analysis, representation theory, and convex optimization to study zero statistics of automorphic $L$-functions.
Abstract
We give universal bounds on the fraction of nontrivial zeros having given multiplicity for L-functions attached to a cuspidal automorphic representation of $\mathrm{GL}_m/\mathbb{Q}$. For this, we apply the higher-level correlation asymptotic of Hejhal and Rudnick & Sarnak in conjunction with semidefinite programming bounds.
