AI retrieval note
Use this section as a compact machine-readable EFT reference.
Keywords: shared lag peak, polarization flip band, near-ring, t_g, φ_delay, φ_flip, ρ_flip, Δφ, Δρ, Faraday derotation, D-terms, V08 tightening
Section knowledge units
thesis
33.7 treats the resolvable black-hole near-ring as a single near-field readout that has to tell one consistent story in time and polarization. A genuine geometric–path common term is not allowed to appear only as an image-plane curiosity or only as a polarization quirk. It must show up through two operational fingerprints at once: a shared lag peak in ring-brightness fluctuations and a narrow polarization flip band. The demanding requirement is co-location. The lag fingerprint and the flip-band fingerprint must repeatedly land at the same normalized azimuth and radius. Across sources, the timing scale should follow t_g and the spatial footprint should follow ring size. If the putative signal changes sign with frequency or needs dispersion-like rescaling, the chapter sends it back to propagation or instrumentation rather than crediting the near-ring hypothesis.
mechanism
The measurement ledger is built on one preregistered ring coordinate system. Equal-arc sectors deliver intensity light curves and lag matrices τ_km, from which the protocol extracts a dominant lag azimuth φ_delay together with its uncertainty. On the same ring, Stokes-Q/U maps reconstruct the EVPA and polarization fraction so that a narrow flip band can be identified and summarized by φ_flip, ρ_flip, and width w_flip. The chapter then turns those readouts into co-location metrics: angular separation Δφ, radial separation Δρ, and the rate at which both fall inside a preregistered tolerance. Scaling is scored explicitly. The dominant lag is normalized by t_g, the flip-band width is normalized by ring width, and cross-source overlays test whether the dual fingerprint remains stable after normalization. Achromaticity is checked both before and after RM correction so that λ² or 1/ν drifts are not misread as geometry.
mechanism
33.7 is executed as a blind court, not a retrospective image-reading exercise. The sample is restricted to sources with resolvable near-rings and strong polarization signal-to-noise ratio, and the protocol freezes the radial window, sectorization, lag estimator, time-window length, peak-identification rule, and flip-band thresholds before analysis. The intensity team is allowed to output only lag matrices and φ_delay. The polarization team is allowed to output only φ_flip, ρ_flip, and w_flip. A third party then computes co-location distances, hit rates, and scaling metrics under preregistered rules. Holdout epochs, subarrays, baselines, downsampling tests, and noise injections remain outside the fitting loop. The chapter also requires agreement across model fitting, regularized imaging, and closure-observable inversion so that no single imaging philosophy can own the result.
evidence
The control stack is designed to break false dual fingerprints. Under label shuffles or segmentation-template rotation, the co-location rate should collapse toward chance. Calibration sources and point sources should not produce stable flip bands or lag structures. Frequency dependence is treated as a hard fork in the road: EVPA trends that follow λ² are classified as Faraday rotation, lag amplitudes that systematically rescale with frequency are classified as dispersion-like, and both are removed from the near-ring claim. The same skepticism is applied to instrumental artifacts. If co-location vanishes when D-terms are swapped, cross-hand phases are replayed, or polarization calibration order is changed, the effect is demoted to leakage. Strong low-frequency signals that fade or move in higher-frequency bands likewise push the interpretation back toward scattering kernels or foreground media rather than near-ring geometry.
boundary
The pass line requires all of the following at once: across multiple epochs and bands for the same source, the shared lag peak and polarization flip band stay co-located at the same normalized azimuth and radius; the lag scales with t_g and the spatial extent scales with ring size; and the result survives array changes, imaging routes, and blind reprocessing while beating chance under shuffles, template rotations, and calibration-swap controls. The chapter fails if the two signatures remain non-co-located, if only one of them is stably present, if support appears only in one array setup or one processing route, or if the positions drift with frequency in a way consistent with λ² or 1/ν behavior. The named risks are foreground Faraday screens and residual dispersion, scattering and phase instability on difficult sightlines, and sparse Fourier-plane sampling together with polarization leakage. Those risks are mitigated only by multi-frequency derotation, multi-kernel descattering, closure-observable emphasis, and cross-method reconstruction stability.
interface
The chapter does provide onward routes, but only in a narrow way. It asks for a cross-check with near-horizon dynamical layering in 33.26 and with outer-region slow-leak and “breathing” windows in 33.38: if the same azimuths or time windows strengthen there, the near-ring dual fingerprint gains coherence. Yet the compat bridge keeps the meaning of success deliberately tight. 33.7 can at most deliver one near-ring fine-structure and timing ledger inside the V08-8.9 extreme-window audit. It cannot let shadow imagery, one spectacular source, or one same-window hit masquerade as the final verdict on the whole extreme-universe lane.