30.4 locks the early-universe side of V30 into a minimal three-observable BBN ledger: using PDG 2024 primordial abundances, one Gaussian likelihood, and k = 1 symmetry between ΛCDM and EFT, it records a large information-criterion gap in favor of EFT while keeping the run explicitly bounded to a deterministic publication-level dataset rather than a full cosmology pipeline.
Use this section as a compact machine-readable EFT reference.
30.4 keeps the BBN side of Volume 30 deliberately small: three primordial-abundance summaries from the PDG 2024 review are enough for the report to ask whether ΛCDM remains unique under a one-parameter fair comparison. Inside that bounded window, the section does not claim to own early-universe ontology. It records that the report places the comparison in its Superiority regime and therefore treats Big Bang uniqueness as overturned at the level of this minimal BBN ledger.
The setup is narrow and symmetric. The likelihood is the sum of three Gaussian terms for D/H, He-4 Yp, and Li7/H. On the ΛCDM side the model uses one baryon parameter η_b with log-linear BBN scaling; on the Energy Filament Theory (EFT) side it uses one parameter τ, with η_eff = τ · η0. Because both sides keep k = 1, the window functions as an auditable fair comparison rather than as a contest between unequal model flexibility.
The reported numbers are not marginal. For the same minimal dataset, the ΛCDM side gives logL = 28.1133, AICc = -50.2266, and BIC = -55.1280, while the EFT side gives logL = 42.3355, AICc = -78.6711, and BIC = -83.5725. The report therefore quotes ΔAICc = -28.44 and ΔBIC = -28.44, taking those gaps as a publication-level superiority verdict. In Volume 30, that should be read as strong support inside this bounded chemistry window, not as a license to universalize beyond it.
The strength of 30.4 comes from symmetry and transparency, but its boundary is equally explicit. The run is deterministic, using η_b = 6.1e-10 and τ = 1.0, and the report states that no MCMC is required for this publication-level minimal dataset. That means the section is not a full BBN pipeline with posterior diagnostics, nuisance expansions, or broader early-universe stress tests. Its claim is narrower: under this minimal three-observable ledger, ΛCDM is not unique.
30.4 should function as the early-chemistry ledger at the front of Volume 30’s early_growth_window. The reproducibility block—bbn_model_eft.py, bbn_model_lcdm.py, bbn_joint_likelihood.py, run_ic_bbn.py, and the logged outputs logL / AICc / BIC / ΔIC—makes this section easy to carry forward as a report asset rather than as free-floating rhetoric. Its natural within-volume handoff is to 30.5, where the early-universe line moves from primordial abundances into the CMB phase-damping window.