# Transfer validation synthesis

## Question tested

Do chamber-defined structural fingerprints of a galaxy's baryonic-acceleration profile improve out-of-sample prediction of gravitational discrepancy when represented as static whole-galaxy compact signatures or fold-local curve components?

## Answer

The tested global architecture did not produce a consistent gain.

### Compact signatures

```
M2 RMSE                    0.188389
M-IP RMSE                  0.194554
M2 − M-IP                 -0.006165
relative improvement      -3.272%
bootstrap 95% CI          [-0.014576, 0.002150]
```

### Full curves

```
M2 RMSE                    0.188389
M2 + all curves RMSE       0.187569
relative improvement       0.435%
positive folds             1 / 5
bootstrap 95% interval    [-0.005244, 0.006939]
```

Correct curve assignment beat shuffled assignment. This confirms that the curves carry galaxy-specific information; the limitation lies in how that information was transferred into the target model.

### Channel decomposition

```
ρ(κ)    +1.142% aggregate; 4 / 5 positive folds
Aκ      +0.457% aggregate; 3 / 5 positive folds
ν       -1.516% aggregate; 1 / 5 positive folds
```

## Scientific contribution

The experiment establishes that:

1. structural identity and predictive transfer are distinct;
2. whole-galaxy static compression is not the strongest use of the fingerprints;
3. channels carry different transfer content;
4. ρ is the leading candidate for local and regime-conditioned follow-up;
5. galaxy-level response heterogeneity is a central clue rather than noise to be averaged away.

This module belongs in the manuscript as an external transfer-architecture section.
