This repository contains the likelihood module for the KiDS-450 correlation function measurements from Hildebrandt et al. 2017 (MNRAS, 465, 1454). Note that this is NOT the original likelihood used for their analysis. However, this likelihood was used for the analysis of Köhlinger et al. 2019 (MNRAS, 484, 3126) and differences with respect to the original CosmoMC likelihood were found to be negligible (please refer to Section 4.1 in that reference for details). The module will be working 'out-of-the-box' within a MontePython and CLASS (version >= 2.6!) setup. The required KiDS-450 data files can be downloaded from the KiDS science data webpage and the parameter file for reproducing the fiducial run of Köhlinger et al. 2019 (MNRAS, 484, 3126) is supplied in the subfolder INPUT within this repository.

Assuming that MontePython (with CLASS version >= 2.6) is set up (we recommend to use the MultiNest sampler!), please proceed as follows:

1. Clone this repository

git clone https://github.com/fkoehlin/kids450_cf_likelihood_public.git

2. Copy __init__.py and kids450_cf_likelihood_public.data from this repository into a folder named kids450_cf_likelihood_public within /your/path/to/montepython_public/montepython/likelihoods/.

(you can rename the folder to whatever you like, but you must use this name then consistently for the whole likelihood which implies to rename the *.data-file, including the prefixes of the parameters defined in there, the name of the likelihood in the __init__.py-file and also in the *.param-file.)

3. Set the path to the data folder (i.e. KiDS-450_COSMIC_SHEAR_DATA_RELEASE from the tarball available from the KiDS science data webpage) in kids450_cf_likelihood_public.data and modify parameters as you please (note that everything is set up to work with kids450_cf.param).

4. Copy the folder CUT_VALUES from this repository also into the root data folder (KiDS-450_COSMIC_SHEAR_DATA_RELEASE).

5. Start your runs using e.g. the kids450_cf.param supplied in the subfolder INPUT within this repository.

6. Contribute your developments/bugfixes to this likelihood (please use a dedicated branch per fix/feature).

7. If you publish your results based on using this likelihood, please consider citing Köhlinger et al. 2019 (MNRAS, 484, 3126) and please follow the instructions on the KiDS science data webpage for referencing all relevant sources for the KiDS-450 data. Please cite also all relevant references for MontePython and CLASS.

Refer to run_with_multinest.sh within the subfolder INPUT for all MultiNest-related settings that were used for the fiducial runs.

WARNING: This likelihood only produces valid results for \Omega_k = 0, i.e. flat cosmologies!

For questions/comments please use the issue-tracking system!