Exact spherically-symmetric inhomogeneous model with n perfect fluids

Abstract

We present the exact equations governing the dynamics of a spherically-symmetric inhomogeneous model with n decoupled and non-comoving perfect fluids. Thanks to the use of physically meaningful quantities we write the set of 3+2n equations in a concise and transparent way. The n perfect fluids can have general equations of state, thus making the model extremely flexible to study a large variety of cosmological and astrophysical problems. As applications we consider a model sourced by two non-comoving dust components and a cosmological constant, and a model featuring dust and a dark energy component with negligible speed of sound.Comment: 31 pages, 11 figures; matches version accepted for publication in JCAP; added application to clustering dark energy, comparison with previous work on exact solutions, and other minor improvements/reference