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Big Bang Nucleosynthesis

Big Bang Nucleosynthesis reactions

Mass fractions from Big Bang Nucleosynthesis. From Wagoner-Kawano code bbn_new123.f with baryon density \(\Omega_{\rm b} h^2 = 0.0214\) and neutron lifetime \(\tau_n = 885.8 \, {\rm s}\).

“Measurement of the neutron lifetime using a magneto-gravitational trap” (Callahan 2018) gives \(\tau_n = (877.7 \pm 1) \, {\rm s}\).

“Big Bang Nucleosynthesis: 2015” (Cyburt et al. 2016).

PRIMAT (Mathematica code) for computing BBN abundances.

Light Element Abundances from Big Bang Nucleosynthesis

Kirkman, Tytler et al. (2003)
	\(\implies \Omega_{\rm b} h^2 = \) \(0.0214±0.0020\) \(\implies \Omega_{\rm b} = 0.048±0.005\) if \(h = 0.67\)

D/H from Intergalactic Absorption towards Quasar 1243+3047

Kirkman, Tytler et al. (2003)
	Average of 5 quasars including Q1243+3047 \(\implies D/H = 2.8 \pm 0.4 \times 10^{-5}\)

Simulations of the Lyman alpha forest

Davé, Hernquist, Katz & Weinberg (1999)

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Updated 2020 Sep 22