# UNNS Gravity Bridge v0.1 — Frozen Real-Data Protocol

**Protocol status:** FROZEN FOR DATA PREPARATION  
**Execution status:** DATA PREPARED — CHAMBERS NOT RUN

## 1. Registered question

Do the 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 and ordinary profile statistics?

## 2. Scope boundary

Version 0.1 is an incremental-information test. It is not a dark-matter
replacement claim and does not fit lensing, clusters, cosmological growth, or
the CMB. No chamber output is interpreted as a gravitational field.

## 3. Frozen observational corpus

The sole version 0.1 source corpus is SPARC, release associated with Lelli,
McGaugh, and Schombert (2016). The immutable local source layer consists of:

```
data/raw_galaxies/SPARC/SPARC_Lelli2016c.mrt
data/raw_galaxies/SPARC/MassModels_Lelli2016c.mrt
data/raw_galaxies/SPARC/Rotmod_LTG.zip
```

The preparation must fail unless it finds:

- 175 unique catalogue galaxies;
- 3,391 radial mass-model rows across the same 175 galaxies;
- 175 individual `_rotmod.dat` files;
- exact numerical agreement between every individual file and the combined
  mass-model table.

The source files are never modified.

## 4. Frozen baryonic assumptions

The SPARC table supplies `Vdisk` and `Vbul` for mass-to-light ratio one at
3.6 μm. Version 0.1 fixes, rather than fits,

```
Υdisk = 0.5 M_sun/L_sun
Υbul  = 0.7 M_sun/L_sun
```

SPARC `Vgas` already includes the stated factor 1.33 for helium. No further
gas rescaling is applied.

The signed baryonic velocity-squared quantity is

```
Vbar²_signed =
    Vgas*abs(Vgas)
  + Υdisk*Vdisk²
  + Υbul*Vbul²
```

The signed gas term is mandatory. A negative `Vgas` is not replaced by
`abs(Vgas)` or by `Vgas²`; it represents an outward-directed gas force at
that radius.

Using

```
kpc_m = 3.0856775814913673e19
```

the accelerations are

```
gobs = (Vobs² / R) * 1e6 / kpc_m

gbar = (Vbar²_signed / R) * 1e6 / kpc_m
```

in `m s^-2`.

These mass-to-light values define the primary prepared corpus. Changing
either value creates a new preparation branch and protocol revision; it is
not permitted during chamber execution or model fitting.

## 5. Point validity and exclusions

A radial point is retained only when:

1. all required source and derived values are finite;
2. `R > 0`;
3. `Vobs > 0`;
4. `gobs > 0`;
5. `Vbar²_signed > 0`;
6. `gbar > 0`.

Every excluded source row is retained in
`sparc_point_exclusions.csv` with an explicit reason.

Under the frozen preparation, 3,389 of 3,391 source rows are retained. Two
inner points of UGC01281 are excluded because `Vbar²_signed <= 0`. The
galaxy remains in the corpus with its other 23 valid points.

No sigma clipping, curve smoothing, outlier clipping, radial interpolation,
or manual point removal is permitted.

## 6. Registered samples

The prepared galaxy table stores all sample flags.

### PRIMARY

```
quality_flag <= 2
and valid_radial_points >= 10
```

Frozen size: 121 galaxies and 2,975 valid radial rows.

### Registered sensitivity samples

```
INCLINATION_SENSITIVITY:
    PRIMARY and inclination_deg >= 30

RESOLUTION_SENSITIVITY:
    quality_flag <= 2 and valid_radial_points >= 16

STRICT_SENSITIVITY:
    quality_flag <= 2
    and inclination_deg >= 30
    and valid_radial_points >= 16

BROAD_Q12:
    quality_flag <= 2 and valid_radial_points >= 3

Q3_SENSITIVITY:
    quality_flag == 3 and valid_radial_points >= 3
```

Frozen galaxy counts are 115, 75, 74, 163, and 12 respectively.

The PRIMARY sample is used for the registered first result. Sensitivity
branches do not replace it.

## 7. Corrected ladder construction

For each galaxy, use only the retained acceleration values at actual
measured radii:

```
L_G = sort_unique({log10(gbar(R_i))})
```

Rules:

1. `gobs`, `Vobs`, discrepancy, quality flag, and sample labels never enter
   the ladder values.
2. No radial interpolation is performed.
3. No extrapolation is performed.
4. No common ladder length is imposed.
5. Exact duplicate `log10(gbar)` values are deduplicated after sorting.
6. At least three unique values are required for a chamber input.
7. The identical numerical vector is written to both chambers at
   17-significant-digit precision.
8. Ladder length is retained as an ordinary control variable.

Because both chambers sort input, the ladder does not preserve physical
radial order. Route-history language is outside version 0.1.

## 8. Chamber settings

### STRUC-I v1.0.4

- MC runs: 2,000
- κ steps: 40
- κ minimum: 0.01
- κ maximum: 1.0
- repeats: 5
- maximum ladder size: 2,000
- subsampling: forbidden

### STRUC-PERC-I v2.5.0

- adapter: Generic
- κ points: 40
- κ minimum: 0.01
- κ maximum: 1.0
- downsampling: forbidden
- required run status: COMPLETE

The two κ coordinates remain non-interchangeable:

- STRUC-I: `epsilon = κ * median(gaps)`;
- STRUC-PERC-I: `epsilon = κ * IQR(gaps)`, with median fallback when IQR is
  zero.

No subtraction, ratio, or direct equality between chamber κ values is
registered.

**Neither chamber has been run in this deliverable.**

## 9. Chamber signatures

The registered STRUC-I and STRUC-PERC-I signature fields remain those
defined in `config/analysis_specification.json` and
`signatures/chamber_signature_schema.json`. They may be populated only from
canonical chamber exports generated under Section 8.

## 10. Empirical target

```
y(G,R) = log10(gobs(G,R) / gbar(G,R))
```

The target is retained in the prepared profile table for later analysis but
is never used in ladder generation.

## 11. Registered models

- `M0 = log10(gbar)`
- `M1 = M0 + R/R_last`
- `M2 = M1 + ladder length, range, median gap, IQR, gap variance`
- `M_I = M1 + STRUC-I signature`
- `M_P = M1 + STRUC-PERC-I signature`
- `M_IP = M1 + both chamber signatures`

All models use the same fixed Ridge estimator and grouped folds. Entire
galaxies are held out.

## 12. Null battery

The registered branches remain:

- N0 — STRUC-I repeat variability;
- N1 — gap-surrogate ladders preserving ordinary statistics;
- N2 — cross-galaxy chamber-signature reassignment;
- N3 — complete galaxy target-curve permutation.

No null branch is executed before the real chamber signatures exist.

## 13. Interpretation

A positive version 0.1 result requires out-of-sample improvement over both
`M1` and `M2`, survival of relevant nulls, and an effect larger than STRUC-I
repeat variability. A null or negative result is a completed result.

## 14. Current completion state

Completed:

- source corpus frozen and hashed;
- source tables parsed;
- individual ZIP cross-checked exactly;
- accelerations calculated;
- exclusions documented;
- samples frozen;
- 175 paired chamber inputs generated;
- data and ladder validations passed.

Not completed:

- STRUC-I runs;
- STRUC-PERC-I runs;
- chamber signatures;
- model comparison;
- null battery;
- scientific conclusion.

## 15. Change control

Any change to source files, mass-to-light assumptions, signed gas treatment,
point validity, sample criteria, ladder construction, chamber versions,
chamber settings, target, feature sets, split rule, estimator, or null
definitions creates a protocol revision and must be entered in
`CHANGELOG.md` before execution.

---

## 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.

