Fourier optimization and pair correlation problems
Mithun Kumar Das, Tolibjon Ismoilov, Antonio Pedro Ramos
TL;DR
This work develops an axiomatic, Fourier-analytic framework to bound pair-correlation-type form factors for general sequences, linking long-term averages to two extremal Fourier optimization problems and reproducing-kernel Hilbert space methods. By solving EP1 and EP2, and leveraging RKHS structure, the authors derive explicit average bounds applicable to zeros of primitive L-functions in the Selberg class, Dedekind zeta functions, and the real/imaginary parts of zeta along vertical lines. The analysis yields concrete bounds in terms of limiting measures and reproducing kernels, and provides new insight into conjectures on pair correlations, including a counterexample to a conjecture of Gonek and Ki in certain regimes. The results unify several prior averages for L-function zeros under a common framework and supply explicit kernel-based constants for practical bounds. The approach blends harmonic analysis, reproducing-kernel theory, and analytic number theory to quantify how zero patterns constrain average correlations across diverse arithmetic objects.
Abstract
We introduce a generic framework to provide bounds related to the pair correlation of sequences belonging to a wide class. We consider analogues of Montgomery's form factor for zeros of the Riemann zeta function in the case of arbitrary sequences satisfying some basic assumptions, and connect their estimation to two extremal problems in Fourier analysis, which are promptly studied. As applications, we provide average bounds of form factors related to some sequences of number theoretic interest, such as the zeros of primitive elements of the Selberg class, Dedekind zeta functions, and the real and imaginary parts of the Riemann zeta function. In the last case, our results bear an implication to a conjecture of Gonek and Ki (2018), showing it cannot hold in some situations.
