Standard BBN with the Planck baryon density predicts a primordial Li-7 abundance a factor of 3 to 4 above the Spite plateau measured in the oldest stars, while deuterium and helium-4 match beautifully (Cyburt 2008; Fields 2014). The plateau's flatness resists stellar-depletion explanations, laboratory work has closed the nuclear escape routes, and new physics must somehow touch lithium alone.
The model assumes the measured stellar abundances are primordial and the BBN calculation complete, so the factor-of-three gap must be new early-universe physics. That framing has consumed four decades without yield, because any BBN-epoch modification deep enough to fix lithium disturbs the deuterium and helium agreements that anchor the whole framework.
SCT's position on lithium is deliberate honesty rather than a mechanism. The Plasma Equivalence Theorem (P29, P30) and the cascade's termination before one second (P40) guarantee that SCT's BBN is identical to standard BBN: the expansion rate at T = 1 MeV matches the ΛCDM rate to one part in 10³⁹, the same thermal equilibrium weak interactions run (P42), and the same Li-7/H near 4.7 × 10⁻¹⁰ emerges. SCT therefore inherits the lithium problem in full, sharing the factor-of-three discrepancy equally with ΛCDM, and the framework registers this explicitly rather than inventing a collision-flavored escape.
The non-resolution carries information: because SCT's early universe converges exactly onto standard BBN, the framework predicts the lithium solution lies outside cosmology entirely, in stellar depletion physics, nuclear systematics, or abundance-measurement systematics, and cannot lie in any modification of the expansion history, since SCT independently demonstrates that a radically different cosmogenesis still produces the same BBN. The shared-jeopardy registration is in the canonical ledger alongside the cascade-termination constraints of Paper 1, From Chaos to Convergent Foundations, with the spectrum-equivalence machinery in Paper 3, From Chaos To Concordance Spectra.
Keystone economy: P40 and P42 lock SCT to standard BBN; the discipline is in refusing the cheap fix.
NOT RESOLVED. SCT's BBN is identical to ΛCDM's by construction, so the Li-7 deficit is a shared open problem. The framework's registered position: the resolution must lie in stellar or nuclear physics, not in cosmology.
The shared-jeopardy structure cuts distinctively: if the lithium problem is eventually resolved by modified early-universe expansion physics, a cosmological fix, that would refute SCT's cascade-termination chain (P40), which forbids any deviation from standard BBN conditions. Conversely, resolution through stellar depletion or nuclear systematics confirms the registered SCT position. The problem's eventual solution is itself the test.