CosmoTools

This is a lightweight Julia module to compute basic cosmological quantities.

Installation guide

Recommended installation

The recommended way to install CosmoTools is to use the local registry CosmoRegistry following the few steps below in a julia shell

using Pkg

# add the registry to the your own
Pkg.Registry.add(url = "https://github.com/gaetanfacchinetti/CosmoRegistry.git")

# fetch CosmoTools in the local registry
Pkg.add("CosmoTools")

# import CosmoTools
using CosmoTools

For developpers

To develop CosmoTools, you can clone this github repository

git clone https://github.com/gaetanfacchinetti/CosmoTools.git

and install it in a julia shell

using Pkg
Pkg.develop(path = "<path>/CosmoTools.jl")

using CosmoTools

User manual

The fundamental brick of the CosmoTools is the BkgCosmology. You can for instance define a FLRW child as shown below.

using CosmoTools

# Constructor of FLRW cosmology is
# FLRW(h::Real, Ω_χ0::Real, Ω_b0::Real, Ω_k0::Real=0; T0_CMB_K::Real = 2.72548, Neff::Real = 3.04, EdS::Bool = false)
cosmo_bkg::FLRW = FLRW(0.6736, 3.0, 0.0)

# predefined cosmology exists such as
const planck18_bkg::FLRW = FLRW(0.6736, 0.26447, 0.04930)
const edsPlanck18_bkg::FLRW  = FLRW(0.6736, 0.3, 0, EdS = true)

A multitude of functions are then available to compute quantities related to this background cosmology.

# critical density of the Universe
ρ_critical(0.0, cosmo_bkg) 

# age of the universe
universe_age(0.0, cosmo_bkg)

In addition, CosmoTools can be used to evaluate the matter power spectrum with a predefined transfer function and even evaluate the halo mass function from the Press-Schechter formalism.

# define a cosmology from a background cosmology, a primodial curvature power spectrum and a transfer function
# a predifined cosmology is, for instance, that from Planck18 
const planck18::Cosmology = Cosmology("PLANCK18", planck18_bkg, k->power_spectrum_ΛCDM(k, 1e-10*exp(3.044), 0.9649), EH98_planck18)

# the Press-Schechter halo mass function for a top-hat window function in planck18 cosmology at z = 0 is obtained from 
m = 10.0.^range(-5, 16, 200)
dndm = dn_dM.(m, 0, TopHatWindow, PressSchechter; cosmology = planck18, growth_function=growth_factor_Carroll, δ_c = 1.686)

More information

Any comment and contribution is welcome!