Cosmology ParametersΒΆ

The default cosmological parameters in ARES are from Planck. Specifically, we take values from the last column of Table 4 in Planck XIII.

Note

Several input files (e.g., lookup tables for the halo mass function, initial conditions, etc.) depend on these vales. There currently is not a system in place to make sure there is a match between the parameters you pass at run-time and the lookup tables read-in from disk. Beware!

omega_m_0

Matter density, relative to the critical density.

Default: \(\Omega_{m,0} = 0.3089\)

omega_b_0

Baryon density, relative to the critical density.

Default: \(\Omega_{b,0} = 0.0486\)

omega_l_0

Dark energy density, relative to the critical density.

Default \(\Omega_{\Lambda,0} = 0.6911\)

hubble_0

Hubble parameter today.

Default: 0.6774 \([100 \ \text{km} \ \text{s}^{-1} \ \text{Mpc}^{-1}]\)

helium_by_mass

Fractional helium abundance by mass.

Default: 0.2453

cmb_temp_0

Temperature of the cosmic microwave blackbody, today.

Default: 2.7255 \([\text{K}]\)

sigma_8

Default: 0.8159

primordial_index

Default: 0.9667