ΛCDM CAMB spectra unchanged; μ(a) growth matches sim_63 on the same pins — first Boltzmann bridge before sim_72 likelihood.

Purpose

First **CAMB** Boltzmann smoke test: ΛCDM $H(z)$ fixed, SVT $\mu(a)$ only in the growth sector via `context/svt_cosmo.py`.

What it proves

$D_{\rm SVT}/D_{\rm GR}(z=0)$ within 5\% of sim_63; $C_\ell^{TT}(220)$ ratio SVT/GR within 1\%; documents $f_G(z_{\rm CMB})=1$ so BBN expansion is unchanged.

Relation to current theory

Bridges sim_63 ODE growth to a full Boltzmann pipeline; prerequisite for sim_71–72.

Key equation

\mu_{\rm SI}(a)=1+\alpha\,(f_G(a)-1),\quad H(z)\ {\rm fixed\ to\ \Lambda CDM}

Interactive visualization

SVT predictionΛCDM CAMB spectra unchanged; μ(a) growth matches sim_63 on the same pins — first Boltzmann bridge before sim_72 likelihood.

Plots

stdout tail

=================================================================
 SVT Simulation #70: CAMB μ(a) smoke test
=================================================================
  f_G(z_CMB)              : 1.000000  (BBN-safe if 1.0)
  D_SVT/D_GR(z=0)         : 1.2292  (sim_63 ref band [1.01,1.35])
  C_ell_TT[220] (CAMB)    : 5732.43 μK²
  C_ell ratio SVT/GR      : 1.0000  (expect ~1)

=================== VALIDATION ===================
  BBN: f_G(z_CMB)=1          : PASS
  D ratio vs sim_63 band     : PASS
  C_ell TT unchanged (bg)    : PASS
  Overall                    : PASS

  SVT Prediction: ΛCDM CAMB spectra unchanged; μ(a) growth matches sim_63 on the same pins — first Boltzmann bridge before sim_72 likelihood.
==================================================

  Matches data:   YES — Validated