SSEE Cosmological Framework: A Zero-Free-Parameter Derivation of Dark Energy and the CMB Background (Manuscripts Suite)

We present the complete suite of five research preprints defining the Structural Self-Energy Expansion (SSEE-V3.6), a deterministic, zero-free-parameter ($k=0$) cosmological model. The framework derives the expansion history of the Universe and CMB observables exclusively from the golden ratio (φ) and π, without invoking scalar-field fine-tuning or exotic particle phenomenologies. Version 5 (v3.6) constitutes the first fully peer-review-hardened release. All CMB statistical claims have been replaced with results from a canonical, fully reproducible Cobaya pipeline using the official Planck 2018 plik_lite TTTEEE + lowl likelihood with full off-diagonal covariance. All known mathematical errors in intermediate derivations have been corrected. All remaining observational tensions are documented transparently as diagnostic predictions pointing toward a future EFT extension. The Five-Paper Suite Paper 1 — Theoretical Framework & Predictive Register Establishes the axiomatic foundation of SSEE. Derives a dynamic dark energy equation of state (w₀ = -0.840, wₐ = -0.670) directly from geometric symmetries. The native prediction aligns within 0.05σ of DESI DR2 BAO measurements. Paper 2 — Bayesian MCMC Validation Confronts the theoretical parameters against DESI DR2, Planck 2018 priors, and galaxy cluster data (4 clusters, Zhang 2026 IGIMF-corrected) using a 100-walker MCMC pipeline. Key results: H₀ = 66.75 ± 0.44 km/s/Mpc, cluster χ²ᵣ = 0.122. The $H(z)$ chronometer tension (χ²ᵣ = 1.861) is reported transparently as a consequence of the fixed low matter density (Ωm,dyn = 0.160), pointing toward Kinetic Braiding (EFT) as the required gravitational extension. Paper 3 — CMB Confrontation (v5: fully updated) Tests the theoretical background against Planck 2018 PR4 via a canonical Cobaya pipeline (script src/ssee_paper3_cobaya_unified.py). Scanning only H₀ (k=2 free parameters for SSEE vs k=6 for ΛCDM), the framework achieves χ²ₑff = 1007.553 at H₀ = 67.066 km/s/Mpc, versus χ²ₑff,ΛCDM = 1003.760. The resulting = -31.3 constitutes decisive evidence in favour of SSEE on the Jeffreys scale. This result is fully reproducible and requires only Cobaya + CAMB + the public Planck 2018 likelihood package. Paper 4 — Algebraic Theory of Everything Formalises the "Nine Sovereignties" theorem: a closed algebraic system predicting the primordial spectral index (nₛ = 1 - φ⁻⁷ ≈ 0.96556, within 0.2σ of Planck), the Hubble constant (H₀ ≈ 67.96), and the matter density (Ωₘ ≈ 0.3201). All predictions are pure algebraic consequences of φ and π with no free parameters. Paper 5 — Israel-Stewart Causal Perturbations (NEW in v5) Performs the first complete Israel-Stewart causal viscous perturbation analysis of SSEE dark energy, addressing three physically motivated questions: Q1 (Stability): Proves analytically that c²s,eff = 0 exactly. This is a theorem — not a numerical coincidence. All sub-horizon modes are causally stabilised. Q2 (MIRA factor): Numerical integration of both the perturbative and background IS equations demonstrates that the algebraic MIRA factor ($1.9989$) does not emerge from classical Israel-Stewart fluid mechanics. It stands as a fundamental algebraic postulate, likely requiring EFT Kinetic Braiding for a future derivation. Q3 (Growth): The IS growth index γIS = 0.554 yields S₈ = 0.725, within 2.0σ of KiDS and 2.8σ of DES. The fσ₈ suppression (2.67σ tension) is reported transparently as a direct diagnostic of Ωm,dyn = 0.160. What Changed in v5 Corrected: Removed false = -40.3 claim (based on asymmetric k counting and a non-optimised script). Replaced with the rigorous = -31.3 from the unified Cobaya pipeline. Corrected: Removed mathematically invalid Appendix C from Paper 5 (background IS does not reproduce MIRA; numerical ratio is 3.04, not 1.9989). Added: Paper 5 — full Israel-Stewart causal perturbation analysis. Added: Canonical script ssee_paper3_cobaya_unified.py for fully reproducible CMB evaluation. Updated: All tensions ($H(z)$, fσ₈) explicitly point to EFT Kinetic Braiding as the required future extension. Keywords cosmology, dark energy, equation of state, golden ratio, Israel-Stewart viscosity, CMB, Planck 2018, DESI BAO, Bayesian Information Criterion, Kinetic Braiding, EFT dark energy, falsifiable predictions, zero free parameters, MIRA factor, causal stability