DES 1YR linear data cutoff for CosmoMC

The code in this repo is used to produce the linear data cutoffs for the Dark Energy Surver (DES) used in CosmoMC.

This code is used in MGCosmoMC.

The galaxy clustering and weak lensing two point correlations functions provided by the Dark Energy Survey (DES) probe non-linear angular scales. When constraining models that do not have a non-linear clustering prescription (for example Modified Gravity and exotic Dark Energy models) the non-linear data has to be properly removed.

1. Installing:

To install this code on your machine, type the following commands on the terminal

git clone https://github.com/alexzucca90/DES_linear_data

2. Running the code:

To run this code, type the following commands on your terminal

cd DES_linear_data
python DES_linear_cutoff.py -t threshold -c name_of_cutoff

where threshold is a fload that defines the threshold to remove the data and name_cutoff is a string that names the cutoff.

3. Outputs:

The code produces a file ./output/DES_1YR_final_name_of_cutoff_cut.dat that contains the used bins and the angular separation range for the correltaion function.

It also outputs a set of plots (in png and pdf formats) that can be used for visual inspection of the data cuts.

4. Examples:

Standard cutoff

To generate the standard DES linear data cut (see our paper), run

python DES_linear_cutoff.py -t 5.0 -c standard

The code starts elimintaning the point that contributes the most to the Delta Chi^2, then recomputes the Delta Chi^2 and repeats the procedure. The improvement in the Delta Chi^2 is shown in the following plot

and eliminates the data points in the shaded regions below

5. References:

Papers illustrating the method to remove the non-linear data:

• Dark Energy Survey Year 1 Results: Constraints on Extended Cosmological Models from Galaxy Clustering and Weak Lensing
  DES Collaboration
  arXiv:1810.02499 [astro-ph.CO]

• Planck 2015 results. XIV. Dark energy and modified gravity
  Planck Collaboration
  arXiv:1502.01590 [astro-ph.CO]