Suppression of large-scale perturbations by stiff solid

Abstract

Evolution of large-scale scalar perturbations in the presence of stiff solid (solid with pressure to energy density ratio > 1/3) is studied. If the solid dominated the dynamics of the universe long enough, the perturbations could end up suppressed by as much as several orders of magnitude. To avoid too steep large-angle power spectrum of CMB, radiation must have prevailed over the solid long enough before recombination.

14 pages, 1 figure. arXiv admin note: substantial text overlap with arXiv:1401.7004