Spin-1 gravitational waves and their natural sources

TL;DR

This paper explores specific non-vacuum exact gravitational waves with unique symmetry properties, analyzing their polarization and sources, and introduces new classes of waves with particular Killing field characteristics.

Contribution

It characterizes non-vacuum gravitational waves with non-Abelian symmetries and discusses waves with a single light-type Killing field, expanding understanding of gravitational wave solutions.

Findings

Polarization linked to sources

Existence of waves with non-Abelian symmetries

Waves with a single light-type Killing field

Abstract

Non-vacuum exact gravitational waves invariant for a non Abelian two-dimensional Lie algebra generated by two Killing fields whose commutator is of light type, are described. The polarization of these waves, already known from previous works, is related to the sources. Non vacuum exact gravitational waves admitting only one Killing field of light type are also discussed.