MGrowth

MGrowth is a Python package for computing growth factor and rate in various cosmological scenarios.

Installation

Use the package manager pip to install MGrowth.

pip install MGrowth

Requirements

Required python packages:

• numpy
• scipy

For tutorials:

• matplotlib
• camb
• emcee
• getdist

Running MGrowth

import MGrowth as mg

zz = [0.9, 1.2, 1.5, 1.8]
aa = 1./(1.+np.array(zz[::-1])) ##should be increasing

background ={'Omega_m':0.31,
            'h' :0.74,
            'w0': -1.3,
            'wa': 0.4,
            'a_arr': aa}

cosmo1 = mg.LCDM(background)

D, f = cosmo1.growth_parameters()

Available Models

• LCDM: standard cosmological model with fixed $w=-1$
• wCDM: dark energy with constant $w$ which can take any values
• w0waCDM: CPL evolving dark energy $w = w_0 + (1-a)w_a$
• IDE: Interacting Dark Energy also known as dark scattering
• nDGP: normal branch of DGP gravity
• f(R): Hu-Sawicki f(R)
• Linder Gamma: Growth index parametrisation
• Linder Gamma a: Time-dependent growth index
• Interpolated modification of the Poisson equation: $\mu(a)$, e.g. dark energy parametrisation of mu in equation (10)
• Interpolated modification of the Poisson equation: $\mu(a, k)$, e.g. equation (27) (see tests_and_plots_mu.ipynb)
• Interpolated dark energy equation of state: $w(a)$ (see tests_and_plots_w.ipynb)

Documentation

Documentation is available here: http://mgrowth.readthedocs.io/