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Cosmology

In this section we show the structures which specify the cosmology and the value of the parameters. In this moment we support only the $w_0 w_a$CDM cosmology, although we plan to include support to other cosmologies.

CosmoCentral.w0waCDMCosmology — Type
w0waCDMCosmology(w0::Float64 = -1, wa::Float64 = 0, ΩM::Float64 = 0.32,
ΩB::Float64  = 0.05, ΩDE::Float64 = 0.68, Ωk::Float64  = 0.,
Ωr::Float64  = 0., ns::Float64  = 0.96, Mν::Float64  = 0.06,
σ8::Float64  = 0.816, H0::Float64  = 67.)

This struct contains the value of the cosmological parameters for $w_0 w_a$CDM cosmologies:

  • $w_0$ and $w_a$, the parameters in the CPL parameterization

  • $\Omega_M$, $\Omega_B$, $\Omega_{DE}$, $\Omega_R$, and $\Omega_k$ the density parameters for respectively matter, baryons, Dark Energy, radiation, curvature

  • $n_s$, the scalar spectral index

  • $M_\nu$, the sum of the neutrino mass eigenstates in eV

  • $\sigma_8$, the amplitude of the scalar fluctuations

  • $H_0$, the value of the Hubble paramater

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In the remainder of this documentation, we will show how to use CosmoCentral.jl and we will plot several quantities. The assumed values for the cosmological parameters are:

  • $\Omega_M$ = 0.32
  • $\Omega_B$ = 0.05
  • $\Omega_k$ = 0
  • $n_s$ = 0.96
  • $\sigma_8$ = 0.816
  • $h$ = 0.67
  • $M_\nu$ = 0.06 eV
  • $w_0$ = -1
  • $w_a$ = 0

Cosmological Grid

Another import quantity is the cosmological grid, the structure which specifies the grids used to compute the quantities in our calculations.

CosmoCentral.CosmologicalGrid — Type
CosmologicalGrid{T} <: AbstractCosmologicalGrid{T}
ZArray::AbstractArray{T} = LinRange(0.001, 2.5, 300)
KArray::AbstractArray{T} = LogSpaced(1e-5, 50., 1000)
ℓBinCenters::AbstractArray{T} = LinRange(10., 3000., 2991)
ℓBinWidths::AbstractArray{T} = LinRange(10., 3000., 2991)
KLimberArray::AbstractArray{T,2} = zeros(length(ℓBinCenters),
length(ZArray))
KBeyondLimberArray::AbstractArray{T,2} = zeros(100, 1000)

This struct contains several grids:

  • ZArray and KArray, the grids for the PowerSpectrum calculations
  • ℓBinCenters, the $\ell$ grid for the $C_\ell$'s calculations
  • ℓBinWidths, used when computing the covariance matrix
  • KLimberArray, the k grid to evaluate the $C_\ell$'s in the Limber approximation
  • KBeyondLimberArray, the k grid to evaluate the $C_\ell$'s without the Limber approximation
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