Memory Effect for Impulsive Gravitational Waves

TL;DR

This paper investigates the unique memory effects of impulsive gravitational waves, revealing velocity jumps and discontinuous trajectories that differ from smooth wave cases, highlighting novel physical phenomena in spacetime dynamics.

Contribution

It introduces the analysis of impulsive gravitational waves' memory effects, including velocity jumps and trajectory discontinuities, extending understanding beyond smooth wave models.

Findings

Particles exhibit velocity jumps after wave passage.

Trajectories become discontinuous along the wave's propagation direction.

Impulsive waves produce distinct memory effects compared to smooth waves.

Abstract

Impulsive gravitational plane waves, which have a delta-function singularity on a hypersurface, can be obtained by squeezing smooth plane gravitational waves with Gaussian profile. They exhibit (as do their smooth counterparts) the Velocity Memory Effect: after the wave has passed, particles initially at rest move apart with non vanishing constant transverse velocity. A new effect is that, unlike to the smooth case, (i) the velocities of particles originally at rest jump, (ii) the spacetime trajectories become discontinuous along the (lightlike) propagation direction of the wave.