Self-force and radiation reaction in curved spacetime

Abstract

The recent detection of gravitational waves by the Laser Interferometric Gravitational Wave Observatory (LIGO) has finally ushered in the much-awaited era of gravitational wave astronomy. While much remains expected of LIGO and similar ground-based observatories, what shall ultimately succeed (and complement) them are future space-based counterparts sensitive to low-frequency gravitational waves. The modeling of so-called extreme-mass-ratio inspirals (EMRIs) is central to these future missions. EMRIs are binaries consisting of a supermassive black hole and a stellar-mass compact object, and are modeled by point particles moving in black hole spacetimes. Over the past two decades, researchers have vigorously pursued a better understanding of this deceptively simple physical system. Much of the challenge (and excitement) comes from the necessity of incorporating self-force effects or radiation reaction - the effect of a particle's own field on its motion. In curved spacetime, evaluating the self-force on a point particle is highly nontrivial, and its behavior can be quite surprising and unintuitive. Thus we see the promise of gravitational wave astronomy casting new light on a long-cherished problem of theoretical physics.
In this talk, I shall discuss the state-of-the-art in self-force theory and calculations. I shall also survey applications of the theory that go beyond gravitational wave astronomy. Finally, I will end with a personal take on future prospects and a list of interesting open problems.