> **Historical provenance document — superseded.** This file preserves an earlier project state. It is not the current scientific interpretation. The canonical v0.3 position is that galaxy-specific structural fingerprints are reproducible and organized; sampling and preparation sensitivity describe how the fingerprints are expressed rather than negating their existence.

# UNNS Gravity Bridge v0.1 — Real SPARC Corpus Prepared

## Current status

**DATA PREPARED — CHAMBERS NOT RUN**

This package now contains the actual SPARC observational corpus, a frozen
real-data preparation protocol, prepared acceleration profiles, and paired
chamber input ladders. It contains no STRUC-I or STRUC-PERC-I result and no
scientific gravity-bridge conclusion.

## 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?**

Version 0.1 tests incremental information only. It does not claim that dark
matter is absent, that chamber output is a gravitational field, or that UNNS
has derived a modified law of gravity.

## Real source corpus

The unchanged source files are in `data/raw_galaxies/SPARC/`:

- `SPARC_Lelli2016c.mrt`
- `MassModels_Lelli2016c.mrt`
- `Rotmod_LTG.zip`

The files provide 175 galaxies and 3,391 measured radial mass-model rows.
Every one of the 175 individual files in `Rotmod_LTG.zip` was compared with
the combined mass-model table and matched exactly.

Official source: `https://astroweb.case.edu/SPARC/`

Required scientific citation:

F. Lelli, S. S. McGaugh, and J. M. Schombert,
“SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and
Accurate Rotation Curves,” *The Astronomical Journal* **152**, 157 (2016).

## Frozen baryonic calculation

SPARC tabulates `Vdisk` and `Vbul` at stellar mass-to-light ratio one. Version
0.1 freezes the fiducial 3.6 μm values

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

and computes

```
Vbar² = Vgas*abs(Vgas) + 0.5*Vdisk² + 0.7*Vbul²

gobs = (Vobs² / R) * 1e6 / kpc_m
gbar = (Vbar² / R) * 1e6 / kpc_m
```

The signed gas term is intentional. Negative `Vgas` values encode an
outward-directed gas contribution at some inner radii and are not converted
to positive squares.

Two UGC01281 points have non-positive signed `Vbar²` and are documented in
`data/prepared_profiles/sparc_point_exclusions.csv`. The prepared corpus
therefore contains 3,389 valid radial rows.

## Sample branches

| Branch | Frozen criterion | Galaxies | Valid radial rows |
|---|---|---:|---:|
| PRIMARY | Q ≤ 2 and n ≥ 10 | 121 | 2,975 |
| INCLINATION_SENSITIVITY | PRIMARY and inclination ≥ 30° | 115 | 2,897 |
| RESOLUTION_SENSITIVITY | Q ≤ 2 and n ≥ 16 | 75 | 2,414 |
| STRICT_SENSITIVITY | resolution branch and inclination ≥ 30° | 74 | 2,397 |
| BROAD_Q12 | Q ≤ 2 and n ≥ 3 | 163 | 3,269 |
| Q3_SENSITIVITY | Q = 3 and n ≥ 3 | 12 | 120 |

The registered model comparison defaults to the PRIMARY branch.

## Corrected ladder

For galaxy `G`, the chamber ladder is

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

using only retained **measured radial samples**. There is:

- no interpolation;
- no extrapolation;
- no forced common ladder length;
- no use of `Vobs`, `gobs`, discrepancy, or dark-matter quantities.

The same value vector is written to both chambers:

```
ladders/chamber_inputs/struc_i/<galaxy>.csv
ladders/chamber_inputs/struc_perc_i/<galaxy>.txt
```

All 175 paired inputs have been generated and validated. The PRIMARY input
list contains 121 galaxies.

## Prepared outputs

`data/prepared_profiles/` contains:

- `galaxy_profiles.csv` — canonical analysis input;
- `sparc_profiles.csv` — identical named SPARC copy;
- `sparc_galaxies.csv` — galaxy metadata and sample membership;
- `sparc_point_exclusions.csv` — the two excluded source rows;
- `rotmod_crosscheck.csv` — 175 exact ZIP/combined-table checks;
- `sparc_preparation_summary.json`;
- `PREPARATION_REPORT.md`.

`ladders/` contains the paired chamber inputs, manifest, hashes, and
registered sample input lists.

## Reproduction commands

From the project root:

```bash
python -m pip install -r requirements.txt

python data/prepare_sparc_corpus.py
python ladders/galaxy_profile_to_ladder.py

python validation/validate_sparc_preparation.py
python validation/validate_ladders.py
```

These commands prepare data only. They do not execute either chamber.

## Canonical instruments

Untouched browser instruments remain in `chambers/canonical/`:

- `chamber_struc_i_v1_0_4.html`
- `struc_perc_i_v2_5_0.html`

Do not run them until the preparation archive and frozen protocol have been
accepted. When chamber work begins, use `chambers/CHAMBER_EXECUTION_GUIDE.md`.

## Scientific boundary

The present deliverable establishes a real observational input layer and
nothing more. `outputs/reports/result_record.json` is marked
`DATA_PREPARED_CHAMBERS_NOT_RUN`. No chamber signature, model comparison,
null result, or gravity claim exists yet.
