The Interior Observer Cosmological Framework Paper 27 — Theorem-Grade Closures for the Scalar-Bridge Perturbation Sector

Beginning from two premises — (1) the observable universe exists inside a Schwarzschild black hole, and (2) the physics inside the horizon is the same as outside — Paper 27 executes the first fully IO-native CLASS Boltzmann code confrontation with Planck 2018 TT data. The IO-native configuration achieves 100θₛ = 1. 04083 (−0. 86σ from Planck) — a zero-parameter prediction of the CMB acoustic scale. The broadband TT spectrum gives χ² (TT) = 2281, a hard failure diagnosed through three rounds as an architectural mismatch: CLASS is a single-baryon bulk simulator, while the IO framework predicts three process-dependent baryon densities from boundary projection. Part II elevates six conditional premises: the Spatial CCR Lift Theorem (Theorem 27. 1, DERIVED/THEOREM), the No-Doubling Theorem upgrade (Corollary 27. 1a, DERIVED/THEOREM), C1a Cross-Term Vanishing (Theorem 27. 2, DERIVED), AV1 Visibility-Slot Inheritance (Theorem 27. 3, DERIVED/THEOREM), and corrections to C1b (Aₛ = 2. 114 × 10⁻⁹, +0. 47σ) and C3 (τₑff = Kgauge = 0. 05488, +0. 12σ). Part III documents the updated conditional debt inventory. Multi-AI adversarial collaboration: Claude (Anthropic), Codex/ChatGPT (OpenAI), Gemini (Google DeepMind). https: //dfife. github. io/index. html v2. 0 (May 2026): Major restructure to a theorem-grade closure paper for the scalar-bridge perturbation sector. Seven new sections §§5–11 establish state-selection boundary characterization on the lifted carrier hᵥec via Theorems 27. 5. 8, 27. 6. 6, 27. 6. 7, 27. 6. 15, 27. 7. 5, 27. 8. 5, 27. 9. 5, 27. 10. 7, and Corollary 27. 10. 8. Headline result: full state selection on hᵥec remains OPEN/PREMISEGAP but is non-damaging for current scalar predictions — residual freedom cannot act as a hidden tuning parameter. Closure boundary recorded in §11 (Theorems 27. 11. 1, 27. 11. 3–27. 11. 6, with Corollary 27. 11. 2). Theorem 27. 2 (C1a) promoted to load-bearing Part I; Theorems 27. 1, 27. 3, Corollary 27. 1a, and H2/H3 retained. Superseded v1. 5 content removed (CLASS confrontation; C1b/C2c/C3 "Results Not Achieved" — covered by Paper 26 v2. 0 and Paper 31). Active labels canonicalized; references list and contributors added. Reproducibility bundle: GitHub Release https: //github. com/dfife/io-framework-public/releases/tag/paper27-v2. 0; tarball SHA256 83bb435818e0fef0944f932a5f84f9f79457ce5f4b9c4a4777bd6b2192ee224e; mirror https: //github. com/dfife/io-framework-public/tree/main/papers/paper27/v2. 0. Validation: 10/10 PASS plus an independent Model Context Protocol (MCP) validation pass. Audit boundary: no active R4 = 1 use, no active independent Cosmic Microwave Background temperature prediction, and no hidden fitted parameter in the active theorem and bundle chain; retired CMB-T scripts excluded and named in the bundle audit report. Claim naming convention: https: //github. com/dfife/io-framework-public/tree/main. v1. 5 (April 2026): Title updated. CLASS results demoted to non-load-bearing (architectural incompatibility). C1b variance ratio KILLED as fitted parameter (IO Law) ; Aₛ = 2. 114 retired, Aₛ = 2. 007 active. Appendix replaced with Paper 26 v1. 1 clean + Paper 27 theorems. Appendix purged to theorem-grade only (30+ non-theorem steps removed: scorecards, kill lists, diagnostics, literature searches, sensitivity tables). Document order corrected. Cosmetic: Schur definitive→conditional Schur, Rosetta→gauge partition, energy→matter projection. v1. 4 (April 2026): Appendix Steps 58 and 60 updated to Schur definitive branch. Website added to title page. All CLASS results in Part I remain on the retired mixed branch (H₀ = 67. 58) as documented in v1. 1 — the mismatch diagnosis is branch-independent. v1. 3 (April 2026): Paper 24 v2. 0 consistency update. TBSb promoted from SEMICLASSICAL PRINCIPLE to DERIVED/SCOPED on the physical Paper 24 TT observable class via the Modular Intertwiner Theorem (Paper 24 v2. 0 §13. 2). Conditional debt table and Appendix C updated. v1. 3 (April 2026): Paper 24 v2. 0 consistency update. TBSb promoted from SEMICLASSICAL PRINCIPLE to DERIVED/SCOPED on the physical Paper 24 TT observable class via the Modular Intertwiner Theorem (Paper 24 v2. 0 §13. 2). Conditional debt table and Appendix C updated v1. 2 (April 2026): Paper 31 consistency update. C3 (τ = Kgauge) KILLED by Paper 31 post-bridge field class no-go theorem: within the scalar primary CMB class, Xₒbs = f_Γ Xₚrim is proved impossible; only Xₒbs = f_Γ^1/2 Xₚrim survives, giving τ = Kgauge/2. The original Paper 26 derivation τ = Kgauge/2 is restored as DERIVED/SCOPED on the reduced source-covariance class, supported by three independent routes. C1b WEAKENED: Paper 31 Weyl-response bridge (ηIO = 0. 623) shows Planck’s GR lensing extraction is biased for IO geometry, removing the observational authority for the C1b correction; both Aₛ candidates (2. 007 native, 2. 114 Planck-calibrated) are now CONDITIONAL. C2c narrowed to C2q: the bridge quotient theorem shows Aₛ depends only on the one-dimensional bridge quotient, not the full δΓ ⊕ δK carrier. All theorem elevations in Part II (§§6-9) are unaffected. Appendix steps 417-420 added with Paper 31 cross-references. v1. 1 (April 2026): Paper 29 branch consistency audit. The CLASS run in Part I (§§2–5) used the retired mixed branch (H₀ = 67. 58, ωcdm = 0. 13029). The Schur definitive branch (H₀ = 68. 91, Ωₘ = 0. 336, Ωₖ = −0. 006) also fails CLASS for the same architectural reason — the mismatch diagnosis is branch-independent. §2 IO-Native Parameter Set annotated. All theorem elevations (Part II §§6–10) are unaffected. v1. 0 (March 2026): First fully IO-native CLASS Boltzmann code confrontation with Planck 2018 TT data: θₛ = 1. 04083 (−0. 86σ from Planck) with χ² (TT) = 2281, diagnosed through three rounds as an architectural mismatch between the IO boundary-projective multi-baryon framework and CLASS's single-baryon bulk simulator. Six theorem promotions: Spatial CCR Lift (Theorem 27. 1), No-Doubling upgrade (Corollary 27. 1a), C1a Cross-Term Vanishing (Theorem 27. 2), AV1 Visibility-Slot Inheritance (Theorem 27. 3), H2 Spatial CCR for WMR (via Theorem 27. 1), H3 Rate is Two-Point (via Theorems 25. 9–25. 11). Two corrections: C1b variance ratio corrected from r=1 (−3. 09σ) to r=1+γ²=Q (q_γ) (+0. 47σ), SEMICLASSICAL PRINCIPLE; C3 propagator identification corrected from τ=Kgauge/2 (−3. 8σ) to τ=Kgauge (+0. 12σ), SEMICLASSICAL PRINCIPLE. Two elevations: C2c Hawking state selection elevated to SEMICLASSICAL PRINCIPLE via horizon-first route; H1 bridge state selection elevated to SEMICLASSICAL PRINCIPLE via minimal spatial KMS extension. Full Aₛ normalization chain audited: Aₛ = (25/9) × fₛrc × gH/√2 with two semiclassical inputs (C1b, C2c), zero continuous parameters. Damped amplitude Aₛ e^-2τ preserved to 0. 3% across both corrections. All seven geometric observables within 1σ of measurement. Independent AlterBBN cross-verification confirms BBN predictions at sub-percent level (Paper 24 v1. 3). Items needing elevation reduced to two: PSRP and Boundary Covariance Exponent. Five-system adversarial AI collaboration.