Averaging out Inhomogeneous Newtonian Cosmologies: I. Fluid Mechanics and the Navier-Stokes Equation

TL;DR

This paper reviews classical fluid mechanics concepts and equations, focusing on their application to Newtonian cosmology and the derivation of averaged Navier-Stokes-Poisson equations, emphasizing physical interpretation.

Contribution

It provides a detailed formulation of fluid mechanics principles tailored for Newtonian cosmology, facilitating the analysis of inhomogeneous cosmological models.

Findings

Formulation of averaged Navier-Stokes-Poisson equations

Clarification of fluid motion definitions in cosmology

Analytic framework for inhomogeneous fluid analysis

Abstract

The basic concepts and equations of classical fluid mechanics are presented in the form necessary for the formulation of Newtonian cosmology and for derivation and analysis of a system of the averaged Navier-Stokes-Poisson equations. A special attention is paid to the analytic formulation of the definitions and equations of moving fluids and to their physical content.