Evolution of perturbations in a universe with exotic solid-like matter

We study cosmological perturbations in a universe with only one matter component described by triplet of fields. Configuration these fields is the same as for body coordinates solid, and they enter Lagrangian through kinetic term. restrict ourselves to cases constant pressure energy density ratio w. Superhorizon have no modes scalar vector tensor decaying or growing at different rates, w>(19−87)/3=̇−0.722 propagate superluminal sound speed. Regarding our universe, results illustrate possible challenges comparing observational data models similar solid inflation, if inflation followed period during which studied model sufficiently good approximation.