The Extreme Gravity Dynamics and Gravitational Waves of Generic Compact Binary Inspirals

Montana State University, Bozeman MT

Investigators

Abstract

Gravitational wave astrophysics has entered a new era of discovery and exploration, with the Nobel-Prize-earning, first detections of gravitational waves by the advanced LIGO and advanced Virgo ground-based observatories. One of the key missions of LIGO and Virgo is to test Einstein's theory of General Relativity where it has never been tested before: where the gravitational force is enormous and violently changing. Gravitational waves encode invaluable information about this extreme gravity regime, especially in the waves produced when black holes and neutron stars collide. The main objective of this award is to develop ready-to-use models to extract and interpret gravitational waves emitted in eccentric and precessing collisions, so that these models can be used to study astrophysics and test General Relativity with future observations. This research will be integrated with broader impact activities aimed at changing the attitudes of K-12 students and the general public toward physics and science through activities that will be developed in the eXtreme Gravity Institute at Montana State University, a fertile training ground for the next generation of scientists. This project is aimed at (i) the development of analytic, ready-to-use models for the orbital dynamics and gravitational waves emitted in the late inspiral of generic compact binaries (black hole and neutron star binaries with arbitrary spin and eccentricity), and (ii) the use of these models to analyze and interpret current and future ground-based gravitational wave data to study astrophysics and experimental relativity implications. The gravitational wave models used currently are restricted to (at most nearly) quasi-circular inspirals with (typically) spins aligned/anti-aligned with the orbital angular momentum (or to simple-precession-like approximations). Such models are sufficient for the detection and characterization of current GW observations, but as advanced LIGO is upgraded to reach design sensitivity and third-generation detectors are constructed, more accurate models will be needed. Not only will these models prevent the biasing of parameter estimation due to mis-modeling systematics, but the additional information they encode will allow for more accurate parameter estimation and the extraction of new information from the data. This new information, such as the orbital eccentricity and the spin vector components, can inform astrophysical population models, as well as allow for new tests of General Relativity in the mostly-unexplored, extreme gravity regime. The proposed research includes the implementation of the ready-to-use models in data analysis studies to determine the astrophysics and experimental-relativity information that can be extracted from current and future gravitational wave data. This research will be integrated with broader impact activities aimed at changing the attitudes of K-12 students and the general public toward physics and science. "The Art of Physics" activity is an art competition and residency program in the Department of Physics at MSU, in which undergraduate students will be educated in cutting-edge physics and create art works that convey its concepts. The art pieces will compete at a juried exhibition, with the winning artist becoming the resident artist in physics for the next year. The "Learn to Fail" activity is an art installation in which Montana State University faculty will share their failure stories with the MSU student population and general public on camera while contrasting their biggest achievements. Through this juxtaposition between failures and successes, the installation will generate an honest dialogue about the role and meaning of failure in academia. "eXtreme Gravity for Middle School? are fully-formed, standards-aligned lesson plans for middle school teachers aimed at supporting them in learning how to deliver content on topics including gravitational lensing, neutron stars, black holes and gravitational waves to middle school students. Other activities include a black-hole themed bout for the local roller derby team, public talks given by the PI, and continued STEM mentoring for middle-school students from local schools. 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.