Cosmology Parameters¶

ComovingCoordinates (external)
Flag (1 - on, 0 - off) that determines if comoving coordinates are used or not. In practice this turns on or off the entire cosmology machinery. Default: 0
CosmologyFinalRedshift (external)
This parameter specifies the redshift when the calculation will halt. Default: 0.0
CosmologyOmegaMatterNow (external)
This is the contribution of all non-relativistic matter (including HDM) to the energy density at the current epoch (z=0), relative to the value required to marginally close the universe. It includes dark and baryonic matter. Default: 0.279
CosmologyOmegaLambdaNow (external)
This is the contribution of the cosmological constant to the energy density at the current epoch, in the same units as above. Default: 0.721
CosmologyOmegaRadiationNow (external)
This is the contribution of all relativistic matter to the energy density at the current epoch (z=0), in the same units as above. Default: 0.0.
CosmologyHubbleConstantNow (external)
The Hubble constant at z=0, in units of 100 km/s/Mpc. Default: 0.701
CosmologyComovingBoxSize (external)
The size of the volume to be simulated in Mpc/h (at z=0). Default: 64.0
CosmologyInitialRedshift (external)
The redshift for which the initial conditions are to be generated. Default: 20.0
CosmologyMaxExpansionRate (external)
This float controls the timestep so that cosmological terms are accurate followed. The timestep is constrained so that the relative change in the expansion factor in a step is less than this value. Default: 0.01
CosmologyTableNumberOfBins (external)
Conversions between time and redshift are computed by interpolating from a numerically integrated table of log(scale factor) vs. time. This parameter sets the number of bins in the table. Default: 1000.
CosmologyTableLogaInitial (external)
This sets the lower bound of the table used to convert between time and redshift. This is log10 of the lowest value of the scale factor. This value will be automatically adjusted if CosmologyInitialRedshift is set to an earlier time. Default: -6.0, (i.e., z = 999,999.)
CosmologyTableLogaFinal (external)
This sets the upper bound of the table used to convert between time and redshift. This is log10 of the highest value of the scale factor. This value will be automatically adjusted if CosmologyFinalRedshift is set to a later time. Default: 0.0, (i.e., z = 0.)
CosmologyCurrentRedshift (information only)
This is not strictly speaking a parameter since it is never interpreted and is only meant to provide information to the user. Default: n/a