.. _cosmology-parameters: 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 ``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 ``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