Gravitational Wave Data Analysis: Parameter Inference and Black Hole Ringdown

University Of Texas At Austin, Austin TX

Investigators

Abstract

This research project is devoted to the analysis and modeling of gravitational waves. These ripples in the fabric of space and time are produced when the densest objects in the Universe -- such as black holes and neutron stars -- orbit and collide. The detection of gravitational waves by the NSF-funded LIGO and European Virgo collaborations has opened up a new window on the Universe, revealing previously invisible events like pairs of black holes merging. Researchers supported by this award will participate in the analysis of gravitational waves as members of the LIGO collaboration, helping to infer the properties of the sources of these ripples. In addition to these collaboration activities, which have far-reaching impacts on astrophysics, cosmology, and nuclear physics, the research group will carry out searches for new physics using gravitational-wave data. Detections of gravitational waves provide information about spacetime at its most dynamic, allowing for strong-field tests of relativity, as the possibility of detecting extremely compact objects which are otherwise invisible to electromagnetic observations. This award will enable both searches for gravitational waves from new, hypothetical compact stars, and study how the final "ringdown" of merged black holes can be used to search for new physics. These research activities will provide training for graduate students in modeling and data analysis, skillsets which are in great demand and of great benefit to society. In addition, members of the group will engage in outreach activities in order to educate and inspire the public about this new field of physics and astronomy. In particular, this project focuses supporting the LIGO Scientific Collaboration by performing Bayesian parameter estimation on detections made in the collaboration's next observing campaign. The PI and other members of the group will participate in the application of parameter estimation pipelines, carrying out inferences on detections made in low latency and helping to plan and execute comprehensive parameter analysis on longer timescales. These inferences are a crucial first step in the use of gravitational waves for understanding the populations of compact objects, inferring the nuclear equation of state from observations of binary neutron stars, testing the theory of relativity, and using gravitational waves to measure cosmic expansion. This project will also involve the investigation of systematic errors in parameter estimation when using cutting edge models, which exhibit complicated parameter degeneracies. The team will also use methods borrowed from quantum mechanical perturbation theory to predict how possible deviations from relativity are imprinted on the ringdown spectrum of spinning black holes. These predictions can be used in the future with Bayesian parameter estimation to constrain or measure the underlying parameters of these models using ringdown signals from binary black hole mergers. 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.