On the Hilbert space derived from the Weil distribution
Masatoshi Suzuki
TL;DR
The paper investigates the Hilbert space $\mathcal{H}_W$ obtained by completing $C_c^\infty(\mathbb{R})$ with respect to the Weil hermitian form arising from the Weil distribution, under the RH. It proves that, assuming RH, $\mathcal{H}_W$ is isomorphic to a de Branges space $\mathcal{H}(E_\xi)$ and to a model space $\mathcal{K}(\Theta_\xi)$ via a Fourier-based isomorphism, tying the arithmetic data encoded by the zeros of $\xi(1/2-iz)$ to a concrete Hilbert-space framework. The authors introduce unconditional constructions $\mathcal{H}_0$ and $\mathcal{K}_0$, which are shown to coincide with $\mathcal{H}_W$ and $\mathcal{K}(\Theta_\xi)$ under RH, yielding an equivalence condition for RH expressed as explicit norm equalities on a screw-line parametrization. They also formulate a Hilbert–Pólya interpretation of $\mathcal{H}_W$, showing that, under RH, the zeros $\Gamma$ appear as eigenvalues of a self-adjoint operator, thereby linking the spectral perspective with the explicit formula. Overall, the work translates RH into equalities between $L^2$-norms in a de Branges/model-space setting and provides a robust, structure-rich platform for further RH investigations.
Abstract
We study the Hilbert space obtained by completing the space of all smooth and compactly supported functions on the real line with respect to the hermitian form arising from the Weil distribution under the Riemann hypothesis. It turns out that this Hilbert space is isomorphic to a de Branges space by a composition of the Fourier transform and a simple map.This result is applied to state a new equivalence condition for the Riemann hypothesis in a series of equalities.
