Non-local gravity and comparison with observational datasets

Understand

We study the cosmological predictions of two recently proposed non-local modifications of General Relativity.

• Both models have the same number of parameters as $\Lambda$CDM, with a mass parameter $m$ replacing the cosmological constant.
• We implement the cosmological perturbations of the non-local models into a modification of the CLASS Boltzmann code, and we make a full comparison to CMB, BAO and supernova data.
• We find that the non-local models fit these datasets as well as $\Lambda$CDM.