Using the DES SV Likelihood
The Dark Energy Survey Science Verification likelihood for the shear two-point measurements released on 21 July 2015 are now available in CosmoSIS, a package for parameter estimation in cosmology.
Here are the steps to using it.
1. Install CosmoSIS
Follow these instructions to install cosmosis (the download may take a while, depending where you are - sorry).
2. Get the development version
At the moment the DES likelihood is only available in the "development" (bleeding edge) branch of CosmoSIS, though this will change soon.
Run the commands:
source config/setup-cosmosis update-cosmosis --develop make clean make
you will get the most up-to-date cosmosis version.
3. Test-run the likelihood
Then you can run an example of the DES-SV cosmic shear likelihood by doing:
4. Explore further
This will just run a test, calculating the likelihood at a single point in parameter space. To explore the likelihood you can change to a real sampler - details are in
examples/des_sv.ini, as are details on what is happening in the likelihood and how to modify and experiment with it. You can also see
examples/des_sv_values.ini for the input parameters, and
examples/des_sv_priors.ini for the priors.
If you are new to CosmoSIS please see our front page for tutorials and reference information.