NumCosmoTransferFuncBBKS

Bardeen, Bond, Kaiser and Szalay (BBKS) transfer function.

This objects implements the Bardeen, Bond, Kaiser and Szalay (BBKS) transfer function. See appendix G from [Bardeen et al. (1986)][XBardeen1986a] [ads].

All three available transfer functions basically follow the same pattern, \begin{equation} T(k) = \frac{\ln \left( 1 + 2.34q \right)}{2.34 q} \left[1 + 3.89 q + (16.1 q)^2 + (5.46 q)^3 + (6.71 q)^4 \right]^{-1/4} \, . \end{equation} The difference is the parameter $q$:

• Cold Dark Matter without baryons (#NC_TRANSFER_FUNC_BBKS_TYPE_NOBARYONS): $$ q = k \frac{(T_{\mathrm{cmb}}/2.7)^2}{\Omega_m h^2} \, .$$

• Cold Dark Matter with baryons (#NC_TRANSFER_FUNC_BBKS_TYPE_BARYONS): $$ q = k \frac{(T_{\mathrm{cmb}}/2.7)^2}{\Omega_m h^2} \frac{1}{\exp\left( -\Omega_b - \sqrt{2h} \frac{\Omega_b}{\Omega_m} \right)} $$

• Cold Dark Matter with baryons but without the radiation term (#NC_TRANSFER_FUNC_BBKS_TYPE_CCL): $$ q = k \frac{1}{\Omega_m h^2} \frac{1}{\exp\left( -\Omega_b - \sqrt{2h} \frac{\Omega_b}{\Omega_m} \right)} $$

Where $T_{\mathrm{cmb}}$ is cosmic microwave background radiation mean temperature today (#nc_hicosmo_T_gamma0), $\Omega_m h^2$ is dimensionless total dust density today multiplied by the reduced Hubble constant, $h$, squared (#nc_hicosmo_Omega_m0h2), $\Omega_b$ is the dimensionless baryon density today (#nc_hicosmo_Omega_b0).