Key points are not available for this paper at this time.
With particular reference to the pancake theory of galaxy formation, the paper calculates the attenuation or amplification of adiabatic perturbations of a Friedmann cosmology before, during, and after the era of hydrogen recombination and matter-radiation decoupling. The calculation is based on a modified two-fluid (baryon, photon) model which maintains accuracy even when the mean free path of the photon fluid becomes arbitrarily large. It is found that in addition to the damping of radiative viscosity and heat conduction before recombination, damping just during decoupling is important. Consequently there is no 'velocity overshoot' of perturbations to increased amplitude (as had been previously proposed); this probably renders the standard pancake model inconsistent with present limits on the microwave anisotropy. Also, the smallest surviving mass scales ('pancake masses') are quite large, e.g., 2 x 10 to the 16th solar masses, about 120 Mpc, for Omega = 0.1.
Press et al. (Sat,) studied this question.