On the Collision of Impulsive Gravitational Waves when Coupled with Null Dust
Abstract
The problem of colliding impulsive gravitational waves is considered when the region of spacetime, after the instant of collision, is filled with a mixture of null dusts moving in opposite directions. The extension of the resulting spacetime, to regions before the instant of collision, shows that null dust follows the leading edges of the impulsive waves, and, further, that one can arrange that the spacetime in these regions is identical with what prevails when a perfect fluid with ∊ = p fills the region after the instant of collision. This ambiguity in the spacetime, after the instant of collision, must be traced to an inherent ambiguity in the nature of null dust and its relation with a perfect fluid with ∊ = p.
 Publication:

Proceedings of the Royal Society of London Series A
 Pub Date:
 February 1986
 DOI:
 10.1098/rspa.1986.0008
 Bibcode:
 1986RSPSA.403..189C
 Keywords:

 Cosmic Dust;
 Gravitational Waves;
 Ideal Fluids;
 Pulsed Radiation;
 SpaceTime Functions;
 Wave Scattering;
 Gauge Theory;
 Null Zones;
 Singularity (Mathematics);
 Astrophysics;
 COSMIC DUST;
 GRAVITATIONAL WAVES;
 IDEAL FLUIDS;
 PULSED RADIATION;
 SPACETIME FUNCTIONS;
 WAVE SCATTERING;
 GAUGE THEORY;
 NULL ZONES;
 SINGULARITY (MATHEMATICS)