Displacement memory and BMS symmetries

Shailesh Kumar

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arXiv · 2109.13082

Displacement memory and BMS symmetries

Shailesh Kumar

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Abstract

This article reviews one of the most intriguing properties of black hole spacetimes known in the literature -- gravitational memory effect, and its connection with asymptotic symmetries, also termed as Bondi-van der Burg-Metzner-Sachs (BMS) symmetries, emerging near the horizon of black holes. Gravitational memory is a non-oscillatory part of the gravitational wave amplitude which generates a permanent displacement for freely falling test particles or test detectors. We highlight a model scenario where asymptotic symmetries appear as a soldering freedom in the context of stitching of two black hole spacetimes, and examine the impact of the interaction between test detectors and horizon shells. Further, we provide a more realistic approach of computing displacement memory for near-horizon asymptotic symmetries which is analogous to the conventional memory originally obtained at asymptotic null infinity.

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Shailesh Kumar. 2021-12-09. Displacement memory and BMS symmetries. https://arxiv.org/abs/2109.13082

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