Phil Bull > SKA modified gravity paper

Extending cosmological tests of GR with the SKA

The code and Fisher matrices used to calculate the results in arXiv:1509.07562 are available to download. Please cite the paper if you make use of them.


The Fisher forecasting code is an extension of RadioFisher. All of the relevant modifications are included in the master git branch, so just follow the instructions to download and run that to get started.

To switch on the modified gravity parameters in the Fisher matrices produced by RadioFisher, add the 'mg' flag to the switches list in or, e.g. replace switches = [] with switches = ['mg',]. Then, run the code as normal. The code will run slower, as it now has to calculate a number of extra terms/cross-terms.

The fiducial values for the MG parameters are defined in radiofisher/, as usual. You can define the scale-dependent growth k-bins by adding the fs8_kbins key to the cosmo dictionary in the * scripts, e.g. cosmo['fs8_kbins'] = [0., 1e-2, 1e-1, 1e0, 1e2].

The plotting scripts are mostly to be found with names like plotting/plot_mg_*.py.

The code to calculate the modified growth rate and growth factor can be found in radiofisher/

Fisher matrices

The set of Fisher matrices used in the analysis can be downloaded as a tarball: mgska_fisher.tar.gz [48 MB, md5sum:1a540c2797df459306f5177bb1c37d32].


The paper is available on arXiv, but you can also download it from here [pdf].