Stellar He Production in a Cold Universe?
A hot Big-Bang model of the Universe is quite successful in explaining the observed Helium abundance together with the 2.7 K microwave background radiation. But one might think of other scenarios as well, for example the mass-energy conversion by nucleosynthesis in stars formed in a cold (no photons or particle pairs) Universe out of density fluctuations (Carr & Rees, 1977; Rees, 1978; White & Rees, 1978). Carr (1977) has discussed Helium production in such a Universe by cosmological nucleosynthesis and showed that Helium decreases as the lepton to baryon ratio (L/N) increases — above L/N > 1.5 no Helium is cosmologically produced at all. He concluded that the observed Helium abundance could only be produced if the ratio was in the range 1.20 < L/N < 1.23, but then an overproduction of heavier elements would be expected. Helium production in massive mass losing stars has been considered by Talbot and Arnett (1971) whose semi-analytic treatment gave a Helium nucleosynthetic yield as great as 0.5. However, Carr (1977) has questioned the certainty of their yields.
KeywordsBlack Hole Heavy Element Initial Mass Function Stellar Nucleosynthesis Helium Production
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