# ISiTGR: Testing deviations from GR at cosmological scales including dynamical dark energy, massive neutrinos, functional or binned parametrizations, and spatial curvature

## TL;DR

This paper presents ISiTGR, an advanced software tool for testing deviations from General Relativity at cosmological scales, incorporating various extensions like dynamical dark energy, massive neutrinos, and spatial curvature, to analyze current cosmological data.

## Contribution

The paper introduces a new version of ISiTGR with support for multiple extensions to the standard cosmological model, enabling comprehensive tests of gravity and dark energy using diverse data sets.

## Key findings

- GR is consistent with current cosmological data in all tested extensions.
- The software supports functional, binned, and hybrid parametrizations of modified gravity.
- Constraints on modified gravity parameters are derived from multiple cosmological data sets.

## Abstract

We introduce a new version of the Integrated Software in Testing General Relativity (ISiTGR) which is a patch to the software CAMB and CosmoMC. ISiTGR is intended to test deviations from GR at cosmological scales using cosmological data sets. While doing so, it allows for various extensions to the standard flat $\Lambda$CDM model. In this new release, we have support for the following: 1) dynamical dark energy parametrizations with a constant or time-dependent equation of state; 2) a consistent implementation of anisotropic shear to model massive neutrinos throughout the full formalism; 3) multiple commonly-used parametrizations of modified growth (MG) parameters; 4) functional, binned and hybrid time- and scale-dependencies for all MG parameters; 5) spatially flat or curved backgrounds. ISiTGR is designed to allow cosmological analyses to take full advantage of ongoing and future surveys to test simultaneously or separately various extensions to the standard model. We describe here the formalism and its implementation in the CMB code, the Integrated Sachs-Wolfe (ISW) effect, and the 3x2 point statistics. Next, we apply ISiTGR to current data sets from Planck-2018, Planck-2015, Dark Energy Survey YR1 release, Baryonic Acoustic Oscillations (BAO), Redshift Space Distortions (BAO/RSD) from the BOSS Data Release 12, the 6DF Galaxy Survey and the SDSS Data Release 7 Main Galaxy Sample, and Supernova from the Pantheon compilation, joint SNLS/SDSS data analysis and the Hubble Space Telescope. We derive constraints on MG parameters for various combinations of the five features above and find that GR is consistent with current data sets in all cases. The code is made publicly available at \url{https://github.com/mishakb/ISiTGR}.