V.D29 — Refinement Drift (Redshift)

The refinement drift z(n_s, n_r) := nu(n_s)/nu(n_r) - 1 is the fractional change in spectral frequency of a null intertwiner emitted at depth n_s and received at depth n_r. It is positive (redshift) when n_s < n_r because the finer spectral resolution at later depths dilutes the original frequency.