Description

This award supports research in relativity and relativistic astrophysics and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. Only a few years ago, the Laser Interferometer Gravitational-wave Observatory (LIGO) began a revolution in our understanding of the universe, with the first gravitational wave (GW) observations of coalescing black holes and neutron stars. These ripples in spacetime carry information otherwise hidden from view, enabling unique insight into the most energetic transient phenomena in our universe. Due to ongoing NSF support, gravitational wave observations now accumulate at an ever-increasing pace. Previously unidentified sources are and will be uncovered. Some, like merging neutron stars, can produce associated and distinctive electromagnetic emission. These new sources and populations may push the frontiers of what we predict can happen, or challenge our capability to interpret what did happen. The physical parameters of individual sources can be estimated from observed signals based on approximate predictions of their gravitational wave and/or electromagnetic emission. Likewise, the physics responsible for an individual source or collection of sources can be deduced from their distinctive or well-measured collective properties, based on models for how they form. The goal of this project is to help produce and interpret this new cosmic census, rapidly and reliably identifying new events and populations to inform follow-up observations and modeling.

This project has two major activities designed to enable multimessenger observations of GW sources to achieve their immense potential. First, the group will construct and operate high-cadence, low-latency parameter and population inference codes for gravitational wave sources. Principally created for interpreting LIGO's concrete observations, the group will also use these codes to assess and mitigate how much astrophysical conclusions depend on key uncertainties: the presence of matter (versus vacuum); the accuracy of our approximations to general relativity; and the significance of each source, given data quality. Second, the team will develop and employ new phenomenological methods with which to interpret the cosmic multimessenger census, emphasizing physically-parameterized and generative approaches based on detailed physical models. One long-term goal of this project is to help assemble the necessary framework for the discovery and interpretation of new high-impact populations, including high-mass and high-mass-ratio binaries; binary neutron stars; neutron star/black hole binaries; and more exotic populations with distinctive observable signatures in their physical parameters. The group will deliver infrastructure to support rapid parameter estimation and source classification to inform multimessenger followup observations.

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.