# GRAV-BRIDGE-I v0.1.0 — Frozen Protocol

## Registered question

Do chamber-defined admissibility and full-pairwise connectivity signatures of a galaxy's
baryonic acceleration profile provide reproducible, out-of-sample information about its
observed gravitational discrepancy beyond local baryonic acceleration, normalized radius,
and ordinary profile statistics?

## Sample

The registered sample is the 121-galaxy SPARC primary sample already used for both structural
chambers. The radial input contains 2,975 valid measured-radius rows. No radial interpolation
was used to create the chamber ladders.

## Target

`y(G,r) = log10(g_obs/g_bar)`.

## Essential correction

All structural models extend M2, not M1. Thus M_I, M_P, and M_IP are tested after ordinary
ladder controls are already present. This isolates incremental chamber information.

## Fixed validation

- Five galaxy-grouped folds.
- Same folds for every model and null branch.
- Equal total fit weight per galaxy.
- Primary metric: galaxy-balanced RMSE.
- Paired galaxy bootstrap for the M2 versus M_IP difference.

## Verdict boundary

A positive statistical result is not a gravity law and is not evidence that dark matter is absent.
It is only evidence that the frozen chamber signatures carry incremental out-of-sample
information about the rotation-curve discrepancy.

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## v0.3 project interpretation

This document belongs to the external transfer experiment. Numerical, technical, protocol, or provenance content above is preserved. The transfer result tests one static global architecture: it does not negate the galaxy-specific structural information carried by the curves. Complete curves retain identity, and ρ is the leading channel for local or regime-conditioned follow-up.

