The Riemann $Ξ$-function from primitive Markovian cycles II: Strip rigidity and divisor identification
Douglas F. Watson
TL;DR
The paper develops a strip-based rigidity framework to compare two canonical analytic constructions of a spectral object arising from a primitive dynamical model: a cycle-spectral determinant $P_N$ and the Archimedean Mellin side linked to the Riemann $Ξ$-function. By introducing the seam ratio $R(w)=\frac{Ξ(2w)}{P_N(w)}$ and its normalized form $\widetilde{R}(w)$, the authors prove that, under holomorphy and sector-control hypotheses, the ratio becomes a zero-free strip-unit on admissible overlap strips, forcing $Ξ(2w)$ and $P_N(w)$ to share the same zero divisor on those strips. The bridge is built via a left-strip continuation of the bilateral Laplace transform $\mathcal{B}\Phi^{\star}$, a boundary identity on the left boundary, and a lift to a strip through a holomorphic extension of a real-analytic bridge between the two sides; the key Mellin-Archimedean identification $F_{\mathrm{arch}}(z)=Ξ(2z)$ ties the two constructions together. The work provides a rigorous, conditional pathway to divisor identification and showcases a general mechanism for real-zero phenomena by combining self-duality, modular splitting, and analytic rigidity, with potential applicability beyond the Riemann zeta context.
Abstract
We compare the Riemann $Ξ$--function to a canonical real-entire reference family arising from the cycle Laplacian developed in Paper I. These spectral determinants have only real zeros by self-adjointness. Our main tool is a rigidity lemma for holomorphic functions on horizontal strips. Applied to a normalized seam ratio linking $Ξ(2\cdot)$ to the reference family, this lemma shows that, under explicit holomorphy and boundary nonvanishing hypotheses verified in the forthcoming Paper III, the seam ratio extends to a zero-free holomorphic function of bounded type on each overlap strip. It follows that, on every admissible overlap strip, $Ξ(2\cdot)$ and the reference family have the same zero divisor.
