# UTFANSWF Research Program — Item 02 Closeout

**Item:** New distributed H0 derivation  
**Date:** 2026-08-17 (America/New_York)  
**Production v23 status:** UNCHANGED / PROTECTED 18-of-18 canonical harness PASS  
**Research verdict:** `PASS_NATIVE_BAO_NODE_DERIVATION__FAIL_FINAL_DISTRIBUTED_H0_SOURCE_COMPLETE_CLOSURE`

## 1. Native BAO node

The retired residual-derived BAO bridge and the historical post-hoc node scan were not used.
Using the full official 13-observable DESI DR2 Gaussian BAO vector in its native `DV/rd`, `DM/rd`, `DH/rd` basis, with the active v23 shared coordinates held fixed,

- Omega_m = 0.301791855309283
- r_d = 146.888735133434 Mpc
- Omega_r = 8.840377135536509e-05

all native BAO observables scale as a single amplitude `s = H_ref/H0`.  The full-covariance GLS solution gives

`H0_BAO = 68.885577672579 km/s/Mpc`

with the Delta-chi2=1 interval

`[68.695294458495, 69.076917968499] km/s/Mpc`.

Goodness of fit:

- chi2 = 10.568840474520
- dof = 12
- chi2/dof = 0.880736706210
- max absolute whitened residual = 1.946758 sigma

Shift from the active v23 Row-20 reference H0 is only

`Delta H0_BAO = +0.148224532985 km/s/Mpc`.

## 2. Downstream source-completeness audit

The old distributed release chain does not survive as a source-complete target-free prediction:

1. **CMB calibration release:** zero.  The old hand-entered `1.022` acoustic calibration was removed from active v23 physics, so it cannot supply the historical positive CMB release term.
2. **GW release:** remains an explicitly labeled residual proxy, not an independently derived H0 channel.
3. **SN geometry release:** the current formula applies a residual-compression efficiency to `H0_local_target - H0_raw`.  Because the local target enters the arithmetic before the final output is frozen, this step is target-conditioned and cannot establish a blind H0 prediction.

For provenance only, if the newly derived BAO node is inserted into the surviving proxy arithmetic, the target-conditioned diagnostic lands at `72.404230738076 km/s/Mpc`.  This number is **not promoted** because the construction explicitly depends on the `73.0` local target and retains the underived GW proxy.

## 3. Disposition

`PASS_NATIVE_BAO_NODE_DERIVATION__FAIL_FINAL_DISTRIBUTED_H0_SOURCE_COMPLETE_CLOSURE`

Item 02 is closed for the current eight-item hardening program unless a new UTFANSWF-native derivation supplies the downstream CMB/GW/SN release terms without target conditioning or proxy substitution.  Do not retune the BAO node toward the old passing scan or the local H0 target.
