Memory, Penrose Limits and the Geometry of Gravitational Shockwaves and Gyratons

Abstract

The geometric description of gravitational memory for strong gravitational waves is developed, with particular focus on shockwaves and their spinning analogues, gyratons. Memory, which may be of position or velocity-encoded type, characterises the residual separation of neighbouring `detector' geodesics following the passage of a gravitational wave burst, and retains information on the nature of the wave source. Here, it is shown how memory is encoded in the Penrose limit of the original gravitational wave spacetime and a new `timelike Penrose limit' is introduced to complement the original plane wave limit appropriate to null congruences. A detailed analysis of memory is presented for timelike and null geodesic congruences in impulsive and extended gravitational shockwaves of Aichelburg-Sexl type, and for gyratons. Potential applications to gravitational wave astronomy and to quantum gravity, especially infra-red structure and ultra-high energy scattering, are briefly mentioned.

64 pages, 14 figures. JHEP version plus new appendix on gravitational spin memory

References in corpus (8)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• The gravitational-wave memory effect
• The Refractive Index of Curved Spacetime: the Fate of Causality in QED
• Fermi Coordinates and Penrose Limits
• Black hole formation in the head-on collision of ultrarelativistic charges
• Gyratonic pp-waves and their impulsive limit
• Apparent horizon formation in the head-on collision of gyratons
• Using Atomic Clocks to Detect Gravitational Waves

Cited by in corpus (13)

• Quantum imprints of gravitational shockwaves
• The First-Order Velocity Memory Effect from Compact Binary Coalescing Sources
• Large Gauge Effects and the Structure of Amplitudes
• A simple analytic example of the gravitational wave memory effect
• Graviton noise on tidal forces and geodesic congruences
• Cut-and-paste for impulsive gravitational waves with $\Lambda$: The geometric picture
• Kundt wave geometries in Eddington-inspired Born-Infeld gravity: New solutions and memory effects
• Hidden symmetries from distortions of the conformal structure
• Memory Effect of Gravitational Wave Pulses in PP-Wave Spacetimes
• Cut-and-paste for impulsive gravitational waves with $\Lambda$: The mathematical analysis
• Gravitational lensing, memory and the Penrose limit
• Classical physics from amplitudes on curved backgrounds
• Interaction of exact gravitational waves with matter