Equilibrium recombination

Ailar

In terms of the conserved baryon/photon ratio η find the CMB temperature and redshift at which recombination ended, as defined by the condition that the photon mean-free scattering rate equals the expansion rate, ne.σT.c = H. Use the Saha equation, assuming the parameters of the ΛCDM model plus the present CMB temperature T0 = 2.725 K and the baryon abundance ΩBh2 = 0.02
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