Smooth sandwich gravitational waves

TL;DR

This paper constructs smooth gravitational waves with two flat regions from homogeneous pp-waves, analyzes test particle motion, and explores the limit to impulsive waves.

Contribution

It introduces a method to generate smooth sandwich gravitational waves from homogeneous pp-waves and examines their properties.

Findings

Explicit test particle motion in these waves.

Limit to impulsive wave solutions.

Characterization of smoothness and asymptotic flatness.

Abstract

Gravitational waves which are smooth and contain two asymptotically flat regions are constructed from the homogeneous pp-waves vacuum solution. Motion of free test particles is calculated explicitly and the limit to an impulsive wave is also considered.