Version 2.01

What is ISiTGR?

ISiTGR is an integrated set of modified modules for the software package CosmoMC for use in testing whether observational data is consistent with general relativity on cosmological scales. This latest version of the code has been updated to allow for the consideration of non-flat universes. It incorporates modifications to the codes: CAMB, CosmoMC, and the ISW-galaxy cross correlation likelihood code of Ho et al. Also included is our independently developed generalized weak lensing likelihood module with data sets for the CFHTLenS weak lensing tomography of Heymans et al and CFHTLens 2D weak lensing measurements from Kilbinger et al.

A detailed explanation of the modifications made to these codes allowing one to test general relativity are described in our papers: arXiv:1109.4583, arXiv:1205.2422, and arXiv:1501.03119.

How to get ISiTGR

New! The two versions of ISiTGR have been consolidated into a single package. The three methods of evolving the parameters used to test general relativity, as described in our paper arXiv:1109.4583, are all contained within the code below. Different evolution methods are chosen by using different .ini files and changing options within those files.

Download ISiTGR


This version of ISiTGR is for the July 2015 version of CosmoMC. The original (flat only) verison of ISiTGR as well as builds for other versions of CosmoMC are available here .

ISiTGR for ƒ(R) models

The modified version of ISiTGR that was used to constrain ƒ(R) models in arXiv:1401.3980 can be downloaded here. It is compatible with the December 2013 version of CosmoMC. For installation instructons, see the ReadMe in the linked tarball file.

Running ISiTGR. (ReadMe)

To run ISiTGR you must first download and install CosmoMC (July 2015 version). You can find download instructions, system requirements, and setup instructions for CosmoMC in the CosmoMC ReadMe. Then, simply copy the contents of the unzipped ISiTGR folder to the CosmoMC folder, edit the Makefile for your compilers, compile using "make isitgr", and you are ready to go. To use the functional evolution of the modified gravity parameters, run the code with an ini file based on test_ISiTGR.ini. To use one of the binning methods run using an ini file based on test_ISiTGR_BIN.ini (Please Note: some changes to these ini files may be may be neccessary in order to run with the Planck 2013 likelihoods). Detailed explanations of the specific options available in ISiTGR are availalble in the ISiTGR ReadMe.

Referencing ISiTGR.

We would ask that when using ISiTGR or a modified version of it, you cite: our papers (arXiv:1109.4583 and arXiv:1205.2422), this website; the original CAMB paper; the original CosmoMC paper; and the papers on original ISW-galaxy cross correlation likelihood by Ho et al and Hirata et al. When using any of the CFHTLenS weak lensing data sets, please cite our paper, the corresponding CFHTLens dataset paper (Heymans et al. or Kilbinger et al.), and follow the CFHTLenS publication guidlines given here.  Additionally, please cite the use of any other datasets already included in the original version of CosmoMC.

Version History

  • 2.01 (Released 07/23/15, this version) Updated to July 2015 version of CosmoMC.
  • 2.0 (Released 05/07/15), Major release upgrade: Consolidated the two versions of the code into a single package, major updates to the likelihood modules for compatibility with the Feb. 2015 version of CosmoMC.
  • 1.2 (Released 01/25/15): Updates for Dec. 2013 version of CosmoMC, new CFHTLenS likelihood module.
  • 1.1.1 (Released 05/29/13): Includes bug fixes (Special thanks to Ana Caramete and Lucia Popa).
  • 1.1: Updated code to allow for non-flat universes when varying the MG parameters.
  • 1.02.1 (Released 04/27/12): Fixed bug in CMB_Cls_simple.f90.
  • 1.02: Updated to January 2012 version of CosmoMC.
  • 1.01.1 (Released 04/27/12): Fixed bug in CMB_Cls_simple.f90.
  • 1.01: Updated to October 2011 version of CosmoMC. BAO module now comes included in CosmoMC (Thanks to Antony Lewis).
  • 1.0: Initial release, for August 2011 version of CosmoMC.


If you have any question or comments about ISiTGR or would like to be updated about with future changes to the code, please feel free to email Jason Dossett at: