Studies of Strong-Gravity Binaries and Their Gravitational Waves

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

This award supports research on the dynamics of binary systems in general relativity, and into characterizing the gravitational waves that such binaries produce. The goal of this work is to improve our understanding of how black holes in binary systems interact with one another, and how their interactions affect the gravitational waves they produce. This work provides a foundation for further observational probes of the dynamics of black holes and ultra-strong gravity. This award also supports “sonifications” of gravitational wave signals, using audio to illustrate how gravitational waves encode source information, as well as online tools for studying the behavior of orbits of spinning black holes. Much of the work supported under this award will use black hole perturbation theory (BHPT), an approach that works well modeling binaries in the large mass ratio limit, when a binary can be regarded as a 'small' object orbiting a large black hole. One planned project investigates how the spectrum of modes excited by binary coalescence varies with the binary's geometry. Substantial progress on this problem was made under prior NSF support; further details including implications for measurement are studied with this award. Other projects include continuing investigations of the dynamics of spinning bodies orbiting black holes, and an analysis of event horizon dynamics in tidally deformed black holes, and studies of the dissipative self force. These projects grew from work that constituted major portions of the Ph.D. theses of graduate students supported by a prior NSF award. Finally, this award supports the development of an open-source version of the PI’s black hole perturbation theory code. A reduced functionality version of this code (restricted to perturbations arising from circular, equatorial orbits) was released in 2018, and has been used by many researchers. The full version will likely be an even more useful product for many colleagues. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.