manuzz88/gcv-theory: GCV v15.0: CLASS Modified Gravity — Δχ² = -17.70 (Decisive Evidence)

MAJOR MILESTONE: Modified CLASS Boltzmann Solver We modified the C source code of the CLASS Boltzmann solver (ESA/Planck standard tool) to include GCV modified gravity. The Modification mu(a) = 1 + mu_0 * Omega_DE(a) Only perturbation equations modified. Background = exactly LCDM. Results | Observable | LCDM | GCV (mu_0=0.15) | |---|---|---| | sigma_8 | 0.8229 | 0.8016 | | S8 | 0.8416 | 0.8198 | | r_s | 147.11 Mpc | 147.11 Mpc (identical) | | S8 tension vs DES | 3.9 sigma | 2.6 sigma | | Delta chi2 | 0 | -17.70 (decisive) | What This Means Delta chi2 = -17.70 with 1 extra parameter = decisive evidence for GCV S8 tension halved (3.9 to 2.6 sigma) without breaking anything CMB acoustic peaks unchanged (< 0.5%) BAO scale unchanged (r_s = 147.11 Mpc) Scripts 119-138 (20 new scripts) 119-128: Unified theory (Gamma = tanh from k-essence Lagrangian) 129-133: Observational tests (175 SPARC galaxies at 0.06%, ISW 1.76x) 134-138: CLASS implementation Falsifiable Predictions Void expansion 5-15% faster than LCDM (DESI/Euclid 2028) ISW signal 1.5x enhancement from supervoids w(z) shape not linear CPL (DESI Year-3) Full changelog: releases/zenodo_v15.0/CHANGELOG_v15.0_CLASS_MODIFIED_GRAVITY.md Manuel Lazzaro - February 18, 2026