Exact spherically-symmetric inhomogeneous model with n perfect fluids

TL;DR

This paper derives exact equations for a spherically symmetric inhomogeneous cosmological model with multiple perfect fluids, allowing for flexible equations of state and applications to diverse astrophysical scenarios.

Contribution

It introduces a concise formulation of the dynamics of inhomogeneous models with multiple non-comoving perfect fluids, extending previous models with greater flexibility.

Findings

Model with two non-comoving dust components and a cosmological constant analyzed.

Model with dust and dark energy with negligible sound speed studied.

Equations are formulated in a transparent, physically meaningful way.

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.