Scalar perturbations in a Friedmann-like metric with non-null Weyl tensor

TL;DR

This paper analyzes the stability of a specific cosmological model with a non-zero Weyl tensor and primordial magnetic fields using a covariant, gauge-invariant perturbation approach.

Contribution

It performs a linear scalar perturbation analysis of a Friedmann-like metric with non-null Weyl tensor, extending previous solutions to include stability considerations.

Findings

Demonstrates gravitational stability under scalar perturbations

Provides a covariant, gauge-invariant framework for perturbation analysis

Connects theoretical models with observational quantities

Abstract

In a previous work the authors have solved the Einstein equations of General Relativity for a class of metrics with constant spatial curvature, where it was found a non vanishing Weyl tensor in the presence of a primordial magnetic field with an anisotropic pressure component. Here, we perform the perturbative analysis of this model in order to study the gravitational stability under linear scalar perturbations. For this purpose, we take the Quasi-Maxwellian formalism of General Relativity as our framework, which offers a naturally covariant and gauge-invariant approach to deal with perturbations that are directly linked to observational quantities.