Gravitational Wave Memory In dS${}_{4+2n}$ and 4D Cosmology

Abstract

We argue that massless gravitons in all even dimensional de Sitter (dS) spacetimes higher than two admit a linear memory effect arising from their propagation inside the null cone. Assume that gravitational waves (GWs) are being generated by an isolated source, and over only a finite period of time. Outside of this time interval, suppose the shear-stress of the GW source becomes negligible relative to its energy-momentum and its mass quadrupole moments settle to static values. We then demonstrate, the transverse-traceless (TT) GW contribution to the perturbation of any dS${}_{4+2n}$ written in a conformally flat form -- after the source has ceased and the primary GW train has passed -- amounts to a spacetime constant shift in the flat metric proportional to the difference between the TT parts of the source's final and initial mass quadrupole moments. As a byproduct, we present solutions to Einstein's equations linearized about de Sitter backgrounds of all dimensions greater than three. We then point out there is a similar but approximate tail induced linear GW memory effect in 4D matter dominated universes. Our work here serves to improve upon and extend the 4D cosmological results of arXiv:1504.06337, which in turn preceded complementary work by Bieri, Garfinkle and Yau (arXiv:1509.01296) and by Kehagias and Riotto (arXiv:1602.02653).

arXiv comment30 pages, 1 figure

References in corpus (6)

• Asymptotics with a positive cosmological constant: III. The quadrupole formula
• BMS in Cosmology
• Gravitational wave memory in de Sitter spacetime
• Generation of gravitational waves by generic sources in de Sitter space-time
• Transverse-Traceless Gravitational Waves In A Spatially Flat FLRW Universe: Causal Structure from Dimension Reduction
• A Line Source In Minkowski For The de Sitter Spacetime Scalar Green's Function: Massless Minimally Coupled Case

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