On the current status of Modified Gravity

Understand

We revisit the cosmological viability of the Hu $\&$ Sawicki modified gravity scenario.

• The impact of such a modification on the different cosmological observables, including gravitational waves, is carefully described.
• The most recent cosmological data, as well as constraints on the relationship between the clustering parameter $\sigma_8$ and the current matter mass-energy density $\Omega_m$ from cluster number counts and weak lensing tomography, are considered in our numerical calculations.
• The strongest bound we find is $|f_{R0}| < 3.7 \times 10^{-6}$ at $95\%$~CL.