Purely radiative irrotational dust spacetimes

TL;DR

This paper characterizes a specific class of irrotational dust spacetimes that are purely radiative, showing that certain homogeneous models are uniquely identified by the diagonal property of the magnetic part of the Weyl tensor.

Contribution

It provides a unique characterization of Bianchi class A dust models within purely radiative irrotational dust spacetimes based on the diagonalization of H.

Findings

Bianchi class A models are uniquely characterized by diagonal H.

Purely radiative condition implies specific geometric constraints.

The study advances understanding of non-linear irrotational dust spacetimes.

Abstract

We consider irrotational dust spacetimes in the full non-linear regime which are "purely radiative" in the sense that the gravitational field satisfies the covariant transverse conditions div(H) = div(E) = 0. Within this family we show that the Bianchi class A spatially homogeneous dust models are uniquely characterised by the condition that $H$ is diagonal in the shear-eigenframe.