Physics and Astrophysics of Compact Binaries

Johns Hopkins University, Baltimore MD

Investigators

Abstract

This award supports research in relativity and relativistic astrophysics, and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. This award supports studies of gravitational wave observations to gain a deeper understanding of gravity and black holes. Large financial resources have been invested in advanced detector design on the experimental side, and in a community effort to build compact binary detection templates on the theoretical/data analysis side. The first gravitational-wave detections by the LIGO/Virgo collaboration were a major milestone, but for gravitational-wave science to make even more groundbreaking contributions we must be able to go beyond detections, extracting fundamental physics from the strong-gravity dynamics of the sources. With the expected increase in volume coverage of LIGO/Virgo in the next observing runs, the operation of KAGRA in Japan, the completion of the Cosmic Explorer Horizon Study, and the inclusion of the Einstein Telescope in the 2021 ESFRI Roadmap, this work is timely, geared at enhancing the science scope of ground-based interferometers. The project will train students in a highly interdisciplinary field that requires expertise in general relativity, astrophysics, data analysis and high-energy physics. The students will benefit from interactions with a large international network of world-leading experts in gravitational physics. The projects supported by this award are strongly intertwined, but for convenience they can be grouped in two main research areas: (1) "black hole spectroscopy", i.e. the research program trying to identify merger remnants as the black holes predicted by general relativity from their oscillation frequencies; and (2) ameliorating systematic effects in gravitational-wave astronomy. The first set of projects investigates the detectability of multiple ringdown modes, the measurability of their frequencies, the construction of better models for the ringdown mode amplitudes, and instabilities in quasinormal mode spectra. The second set studies how systematics could affect single-event parameter estimation within general relativity, lead to false “detections” of effects beyond general relativity, and limit our ability to test general relativity and observe gravitational lensing. The PI's group will study the effect of systematics on parameter estimation, tests of general relativity and detection of lensing effects, at both the single-event and population levels. The knowledge gained will be used to devise self-correcting strategies to ameliorate the effect of systematics as we enter the Big Data regime of third-generation interferometers. 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.