Assessing the impact of bulk and shear viscosities on large scale structure formation

The effects of both bulk and shear viscosities on the perturbations relevant for structure formation in late time cosmology are analyzed. It is shown that shear viscosity can be as effective as the bulk viscosity at suppressing the growth of perturbations and delaying the nonlinear regime. A statistical analysis of the shear and bulk viscous effects is performed, and some constraints on these viscous effects are given.