Scalar and vector perturbations in a universe with nonlinear perfect
  fluid
  We study a three-component universe filled with dust-like matter in the form
of discrete inhomogeneities (e.g., galaxies) and perfect fluids characterized
by linear and nonlinear equations of state. Within the cosmic screening
approach, we develop the theory of scalar and vector perturbations. None of the
energy density contrasts associated with the distinct components is treated as
small. Consequently, the derived equations are valid at both sub- and
super-horizon scales and enable simulations for a variety of cosmological
models.
