A Combined Light-Element Fit to the Bounce Temperature: Helium, Deuterium and Helium-3 Together

Individual abundances each constrain a modified cosmology, but they do not constrain it independently in a statistical sense, and quoting the strongest single bound understates what the full pattern of abundances says. The combined statistic is decisive at low bounce temperatures: at 0.5 MeV the chi-square reaches 86.0, and at 1 MeV it is 56.65, both far beyond any acceptable fit for three data points, while the best region, around 15 MeV and above, returns a chi-square of 0.0. Jointly, with the statistic driven principally by helium and reinforced by the other two, the light elements exclude a bounce below roughly the few-megaelectronvolt scale more firmly than any one of them does alone, and they do so without any single measurement being asked to carry more weight than its uncertainty allows. Computed from stated assumptions, not measured.