Model Independent Tests of Cosmic Growth vs Expansion

Understand

We use Gaussian Processes to map the expansion history of the universe in a model independent manner from the Union2.1 supernovae data and then apply these reconstructed results to solve for the growth history.

• By comparing this to BOSS and WiggleZ large scale structure data we examine whether growth is determined wholly by expansion, with the measured gravitational growth index testing gravity without assuming a model for dark energy.
• A further model independent analysis looks for redshift dependent deviations of growth from the general relativity solution without assuming the growth index form.
• Both approaches give results consistent with general relativity.