Impulsive waves in electrovac direct product spacetimes with Lambda

TL;DR

This paper constructs a comprehensive family of non-expanding impulsive waves in electrovac direct product spacetimes, including new solutions in Plebanski-Hacyan universes with a cosmological constant, extending previous models.

Contribution

It introduces a new explicit class of impulsive waves in Plebanski-Hacyan spacetimes with Lambda, expanding the understanding of impulsive solutions in these geometries.

Findings

New impulsive wave solutions in Plebanski-Hacyan spacetimes with Lambda

Recovery of pp-waves when Lambda=0

Description of gravitational waves from null particles with multipole structure

Abstract

A complete family of non-expanding impulsive waves in spacetimes which are the direct product of two 2-spaces of constant curvature is presented. In addition to previously investigated impulses in Minkowski, (anti-)Nariai and Bertotti-Robinson universes, a new explicit class of impulsive waves which propagate in the exceptional electrovac Plebanski-Hacyan spacetimes with a cosmological constant Lambda is constructed. In particular, pure gravitational waves generated by null particles with an arbitrary multipole structure are described. The metrics are impulsive members of a more general family of the Kundt spacetimes of type II. The well-known pp-waves are recovered for Lambda=0.