Testing (modified) gravity with 3D and tomographic cosmic shear

Understand

Cosmic shear is one of the primary probes to test gravity with current and future surveys.

• There are two main techniques to analyse a cosmic shear survey; a tomographic method, where correlations between the lensing signal in different redshift bins are used to recover redshift information, and a 3D approach, where the full redshift information is carried through the entire analysis.
• Here we compare the two methods, by forecasting cosmological constraints for future surveys like Euclid.
• We extend the 3D formalism for the first time to theories beyond the standard model, belonging to the Horndeski class.