Welcome to the CTM module’s documentation!¶
The Cosmological Trajectories Method (CTM) is a perturbative technique to compute the power spectrum and two-point correlation function in real space in the mildly to non-linear regime for a range of cosmologies.
Source and installation¶
The code is available at Github but can also be installed using pip
(all of the dependencies will be automatically installed)
pip install ctmmodule
If pip
fails to install classylss
please follow the following conda
instructions and then retry the installation of the CTM module using pip
.
To install the code from source, first run the following
pip install mcfit
pip install classylss
git clone https://github.com/franlane94/CTM
Then navigate to your .bash_profile (or .profile on Linux machines) and add the following line
export PYTHONPATH="$PYTHONPATH:/DIRECTORY_WHERE_CTM_IS_INSTALLED"
To check the module has been installed correctly run
python
from ctm import CTM
Getting started¶
For a quick start please see the Jupyter notebook. For more detailed examples and information about the code please see the documentation pages.
The default cosmology is Planck18 and the values of key parameters shown in the Table below.
Parameter |
Value |
---|---|
\(H_0\) |
67.66 |
\(\Omega_{cdm}h^2\) |
0.1193 |
\(\Omega_{b}h^2\) |
0.0224 |
\(n_s\) |
0.9665 |
\(\sigma_8\) |
0.8102 |
Note
The units of commonly used variables in this code are:
\(H_0\ [\mathrm{km}\ \mathrm{s}^{-1}\ \mathrm{Mpc}^{-1}]\)
\(k\ [\mathrm{h}\ \mathrm{Mpc}^{-1}]\)
\(\mathrm{P}\left(k\right)\ [\mathrm{Mpc}^3\ \mathrm{h}^{-3}]\)
\(r\ [\mathrm{Mpc}\ \mathrm{h}^{-1}]\)
Citation¶
The CTM module is described in Lane et al. 2021 , if you make use of the CTM module, please include a citation to this work in any publications.
Acknowledgements¶
Please also cite the following papers whose work has featured in the development of both the CTM and this Python module:
Bartelmann et al. 2014 : Kinetic Field Theory (KFT)
Ali-Haimoud 2015 : The trajectories re-derivation of KFT
Hamilton 2000 : FFTLog algorithm on which
mcfit
is basedLesgourgues 2011 : Class, the Boltzmann code on which
classylss
is based
Help and issues¶
If you encounter any issues please either use the Github issues page, or email ctmcodehelp@gmail.com.