D/H Ratio

The ΛCDM Tension

The primordial deuterium-to-hydrogen ratio measured from quasar absorption systems shows scatter and apparent evolution with redshift difficult to reconcile with single-uniform BBN nucleosynthesis (Cooke 2014; Pettini & Conan Doyle 2000). The variation across systems plus uncertainties in stellar deuterium processing suggests systematic observational errors, time-dependent nucleosynthesis, or non-standard early-universe physics.

The ΛCDM Assumption That Creates It

The standard model has BBN producing one universal D/H ratio at the standard baryon density and expansion rate. Recovering observed scatter demands either improved spectroscopy systematics or modified BBN inputs, neither of which is parsimonious within minimal ΛCDM.

SCT Resolution: M2 (Plasma Equivalence Theorem)

SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, the SCT prediction for primordial D/H is identical to ΛCDM at D/H = 2.527 × 10⁻⁵ ± 0.030 × 10⁻⁵ (paper 4210 baked-in). The cascade terminates well before t ≈ 1 second (P40), so BBN proceeds at thermal equilibrium under standard SM thermodynamics (P42), producing the standard D/H yield identically to ΛCDM.

The Plasma Equivalence Theorem (P29, P30) ensures the post-cascade plasma reaches the same six-parameter thermodynamic state as ΛCDM, so D/H is identical at the BBN epoch. Observed redshift-dependent D/H variations across quasar absorption systems therefore reflect post-BBN stellar processing (deuterium destruction in stars) plus systematic measurement uncertainties, not primordial-D/H variations. The cascade-thermalization context (P22, P25) supplies the baryon budget but no distinguishing primordial D/H modification.

The same M2 framework that resolves the broader CMB acoustic-peak structure (recid 25), Ω_b BBN-vs-CMB (recid 171), Y_p (recid 176), and the cascade-thermodynamic post-recombination evolution accounts for D/H as an unmodified standard prediction. Sub-percent observational scatter is shared open issue requiring stellar-processing modeling improvements, not a unique SCT signature.

Falsifier

If precision deep quasar-absorption D/H spectroscopy converges on the standard BBN prediction at the 0.5% level across all systems, the tension is resolved (favoring neither ΛCDM nor SCT). If genuine primordial D/H variation persists, both frameworks face the same challenge.

Premise Grounding

• P22: Physics of superluminal intersections, the cascade-deposition mechanism.
• P25: Pre-existing matter thermalized by collision, supplies the baryon budget.
• P29: Thermodynamic state sufficiency, post-cascade plasma evolution governed by standard physics.
• P30: Six thermodynamic state parameters determine CMB.
• P40: Cascade termination before t ≈ 1 second, BBN proceeds at thermal equilibrium.
• P42: BBN at thermal equilibrium, reproduces standard nucleosynthesis identically.