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.
Shailesh Kumar
Postdoctoral Fellow
I am currently working as a Post-Doctoral Fellow at IIT Kharagpur, India. My research interests broadly lie in the field of various aspects of gravitation theory, with a particular focus on black holes and gravitational waves (GWs). My current research encompasses black hole perturbation techniques, extreme mass-ratio inspirals (EMRIs), gravitational memory, tidal effects and post-Newtonian framework.