Method
NumCosmoHICosmoXHe
Declaration [src]
gdouble
nc_hicosmo_XHe (
NcHICosmo* cosmo
)
Description [src]
The primordial Helium to Hydrogen ratio $$X_\text{He} = \frac{n_\text{He}}{n_\text{H}} = \frac{m_\text{1H}}{m_\text{4He}} \frac{Y_p}{Y_{\text{1H}p}},$$ see nc_hicosmo_Yp_1H() and nc_hicosmo_Yp_4He().