Non-adiabatic perturbations in multi-component perfect fluids
Abstract
The evolution of non-adiabatic perturbations in models with multiple coupled perfect fluids with non-adiabatic sound speed is considered. Instead of splitting the entropy perturbation into relative and intrinsic parts, we introduce a set of symmetric quantities, which also govern the non-adiabatic pressure perturbation in models with energy transfer. We write the gauge invariant equations for the variables that determine on a large scale the non-adiabatic pressure perturbation and the rate of changes of the comoving curvature perturbation. The analysis of evolution of the non-adiabatic pressure perturbation has been made for several particular models.
Cite
@article{arxiv.1011.0569,
title = {Non-adiabatic perturbations in multi-component perfect fluids},
author = {N. A. Koshelev},
journal= {arXiv preprint arXiv:1011.0569},
year = {2011}
}
Comments
11 pages, v2, major revision, some clarifications added, English is improved, results unchanged