Modified Growth with CAMB
This is the official repository for the MGCAMB v3.0 patch. Below there are an introduction to the code and the instructions to install and run the code. This new version of the code was introduced in the paper MGCAMB with massive neutrinos and dynamical Dark Energy
Table of contents
- 1. Introduction
- 2. How to install
- 3. How to run
- 4. What's new
- 5. Examples
- 6. Known Bugs
- 7. Authors List
Modified Growth with CAMB (MGCAMB) is a patch for the Einstein Boltzmann solver CAMB that intrdouces phenomenological Modifications of Growth (MG) along with dynamical Dark Energy (DE). It includes several phenomenological parametrizations. For instance:
- the mu, gamma parametrization, defined as
- the mu, Sigma parametrization, defined as
- the Q,R parametrization, defined as
Structure of the code
The new MGCAMB patch is structured as in the figure.
The parameters in
params_MG.ini are used to run the code and follow the structure above.
Please, note that dynamical DE is supported in the
Consistency of the code
The General Relativity (GR) limit of the code has been tested. The results below show the maximum error obtained in the CMB TT spectrum and matter power spectrum when using the MG equations (in the GR limit) to evolve the system:
GRtrans times, the systematic maximum error is below 0.1%. This is achieved by delaying the time at which the Radiation Streaming Approximation (RSA) is switched on. This slows down MGCAMB code with respect to the default CAMB code by a factor of two.
If you use MGCAMB for your scientific work, please cite the following papers:
MGCAMB with massive neutrinos and dynamical dark energy
Alex Zucca, Levon Pogosian, Alessandra Silvestri, and Gong-Bo Zhao
2. How to install
To install MGCAMB in your machine simply run
git clone https://github.com/sfu-cosmo/MGCAMB.git cd MGCAMB/src/ make camb
3. How to run
Run the code
To run MGCAMB, first modify the
params_MG.ini file according to which models you want to analyze. Then run
Run the test suite
If you want to run the test suite to produce the consistency plots in our paper, then run
cd mgcamb_tests make
4. What's new
With these new version of the code we implemented consistently massive neutrinos, see accuracy plots above, and dynamical dark energy.
Also, the code has been checked and restructured and updated to the CAMB 2018 version.
The MG and DE parametrizations along with the computation of the quantities related to the perturbations are introduced in the file
6. Known Bugs
Fixed Bug in mu-sigma parametrization.
MGCAMB_Gammadotfrom the mu-sigma parametrization was missing the
Fixed. Bug in Hu-Sawicki f(R) gravity:
MGCAMB_Mudotfunctions had a wrong
t1term. Thanks to Ziad Sakr.
7. Authors List
Original Code Developers: