Spectral Flow for the Riemann zeros

Recently, with Mussardo we defined a quantum mechanical problem of a single particle scattering with impurities wherein the quantized energy levels $E_n (σ)$ are exactly equal to the zeros of the Riemann $ζ(s)$ where $σ= \Re (s)$ in the limit $σ\to 1/2$. The S-matrix is based on the Euler product an