The Interior Observer Cosmological Framework: Paper 6 - The Full CMB Power Spectrum in Black Hole Cosmology: A CLASS Boltzmann Code Analysis

Paper 6 in the Interior Observer (IO) cosmological framework, which proposes the observable universe exists inside a Schwarzschild black hole. The full CMB TT angular power spectrum is computed using the CLASS Boltzmann code (v3. 3. 4) with IO framework parameters (H₀ = 58. 2 km/s/Mpc, Ωₘ = 0. 197, Ωₖ = −0. 130, TCMB = 2. 6635 K) and ΛCDM primordial parameters (Aₛ, nₛ, τᵣeio). ΛCDM validation passes: ℓ₁ = 221, matching Planck. The IO spectrum is a clean geometric rescaling of ΛCDM — all five acoustic peaks are shifted uniformly ~17% to larger angular scales (ℓ₁ = 180, ℓ₂ = 445, ℓ₃ = 690, ℓ₄ = 950, ℓ₅ = 1204). Peak spacing, odd-even asymmetry, damping tail, and baryon loading physics are preserved. The first peak is 33% taller due to enhanced early integrated Sachs-Wolfe effect from earlier matter-radiation equality (zₑq = 1748 vs 3403). The IO framework does not break plasma physics — it changes the geometric ruler. A two-dimensional parameter sensitivity scan over Ωₘ ∈ 0. 15, 0. 315 and Ωₖ ∈ −0. 20, −0. 02, with H₀ derived self-consistently from the IO geometric constraint, reveals that ℓ₁ is structurally locked to 171, 198 across the entire viable parameter space. No combination of IO parameters can reproduce ℓ₁ = 220 without requiring H₀ 1100 without altering the late-time BAO fit — notably the same requirement identified by the broader cosmology community for the Hubble tension. All CLASS outputs independently verified by analytical computation (Wolfram/ChatGPT 5. 3). Peak positions are zero-parameter IO predictions; absolute peak heights are not claimed (borrowed Aₛ). Relative peak ratios (including the eISW first-peak enhancement) are emergent physical properties of the IO matter-radiation equality epoch. Multi-AI research: Claude Code (Anthropic) for CLASS computation and parameter scan; Wolfram/ChatGPT 5. 3 (OpenAI + Wolfram) for analytical verification; Gemini 2. 5 Pro (Google DeepMind) for adversarial review; Claude (Anthropic) for orchestration. v1. 1 (Paper 12, DOI: 10. 5281/zenodo. 18936508): Baryon sector annotations per Paper 12 (Baryon Dictionary Principle). Paper 12 derived fb = 2γ/x = 0. 313, superseding the BAO-optimized fb ≈ 0. 25 used in this paper's CLASS computation. Under the BDP: ωb, geom = 0. 02108 (vs. 0. 01694 at fb = 0. 25). The CLASS computation was performed at the old ωb; the parameter scan table remains valid at each scanned fb. Paper 11 subsequently derived the baryon correction F = 1. 381 which, combined with the BDP, gives θ* within 0. 5σ of Planck and ℓ₁ = 220. The geometric peak shift diagnosis, parameter sensitivity scan methodology, and root cause analysis are unaffected. Companion to Paper 1 (DOI: 10. 5281/zenodo. 18854813), Paper 2 (DOI: 10. 5281/zenodo. 18868612), Paper 3 (DOI: 10. 5281/zenodo. 18876346), Paper 4 (DOI: 10. 5281/zenodo. 18883069), and Paper 5 (DOI: 10. 5281/zenodo. 18889865).