The Cosmological Lithium Problem Through the Lens of GCST Global Complexity–Stability Theory as a Resolution to the ⁷Li Discrepancy in Big Bang Nucleosynthesis

Abstract Standard Big Bang nucleosynthesis (BBN) predicts primordial abundances of light elements with high precision for hydrogen and helium-4, yet overproduces lithium-7 by a factor of ~2.5–3.5 compared to observations in metal-poor halo stars (A(Li) ≈ 2.2–2.3 dex observed vs. ~2.6–2.7 dex predicted). Global Complexity–Stability Theory (GCST) resolves this “cosmological lithium problem” as a non-equilibrium structural debt accumulation during the narrow temperature window T ≈ 0.08–0.03 MeV (t ≈ 100–300 s). The stability index drops below ~1, forcing partial quenching of the key production channel ³He(α,γ)⁷Be → ⁷Be(e⁻,ν)⁷Li. The suppression of ⁷Be production is the primary driver of the lithium deficit, as ⁷Li is chemically fragile and mostly exists as ⁷Be until recombination.¹ GCST thus reframes the lithium discrepancy not as missing physics, but as the thermodynamic signature of declining stability under rapid complexity growth in the early universe.