Constraining modified growth patterns with tomographic surveys

Understand

Viable models of modified gravity designed to produce cosmic acceleration at the current epoch, closely mimic the $\Lambda$CDM model at the level of background cosmology.

• However, this degeneracy is generically broken at the level of linear perturbations, where the modifications induce a peculiar scale-dependent pattern.
• A similar pattern is expected in models of coupled dark energy.
• I present the main results published in Pogosian and Silvestri [1], on the growth of structure in f(R) theories of gravity, and in Zhao et al.