Modified gravity versus shear viscosity: imprints on the scalar matter perturbations

C. M. S. Barbosa, H. Velten, J. C. Fabris +1

Cosmological scalar perturbation theory studied in the Newtonian gauge depends on two potentials $\Phi$ and $\Psi$. In General Relativity (GR) they must coincide ($\Phi =\Psi$) in the absence o…