The Lithium-7 Discrepancy as a Test of Bounce Timing: Why a Slowed Expansion Moves the Yield the Wrong Way

The lithium problem is a factor-of-three disagreement that has resisted decades of work: standard nucleosynthesis predicts a lithium-7 abundance near 4.7 in ten billion, while the oldest stars show a plateau near 1.6 in ten billion. The computation shows the bounce moving the predicted abundance in the wrong direction for this discrepancy: at a bounce temperature of 0.15 MeV the prediction rises to 5.29e-10, a factor 3.3 above the plateau value, compared with the standard factor of 2.94. The lithium discrepancy therefore cannot be assigned to bounce timing within this framework, and any version of the framework that claims otherwise fails its own arithmetic. That negative result is itself a usable constraint, because it removes one free explanation and forces the discrepancy back onto stellar depletion or nuclear rates. Computed from stated assumptions, not measured.