Collaborative Research: Massively Parallel Simulations of Compact Objects

University Of Utah, Salt Lake City UT

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. The LIGO and VIRGO gravitational wave detectors are beginning to make new discoveries on a weekly basis. The gravitational waves that they detect are generated in the mergers of two compact objects, such as black holes or neutron stars. Gravitational waves carry important information about their origin that can extracted through careful comparisons to theoretical calculations, such as full-scale computer simulations of binary mergers. This project will study mergers of binary neutron stars and black holes using computer simulations created by Dendro-GR, a new computer code that runs very efficiently on the largest supercomputers. This work will also help push forward current computational capabilities to permit better and faster waveform calculations to be made. These efforts will aid in expanding the use of gravitational wave detections from confirming general relativity to providing additional, even more stringent tests of both the theory and other possible competing theories. Combining data from computer simulations with both gravitational and electromagnetic observations will allow us to probe, in a manner heretofore impossible, the physics of black holes and neutron stars, of gamma-ray bursts, of kilonovae and supernovae, and of even the formation of the heaviest elements on the periodic table. Work done for this project will promote the progress of science and contribute to undergraduate and graduate training in multiple STEM fields including computer science, mathematics, and physics. Finally, Dendro-GR is an open source project. The overarching purpose of this project is to study the dynamics of merging binary compact objects at the frontier of current computational capabilities. The wavelet-based refinement and computational efficiency of Dendro-GR allows the modeling of a wider variety of possible merger scenarios, enhancing the ability to both detect and understand these high-energy events, as well as search for possible new physics beyond our current gravitational models. The efforts will be directed primarily at the following goals: (1) Deploying new computational algorithms and abilities to determine gravitational waveforms for binary neutron star inspirals and mergers of sufficient accuracy that they are usable in improved waveform catalogs. (2) Investigating binary black hole inspirals and mergers with large mass ratios both to understand this class of largely unexplored binaries and to expand the range of current waveform catalogs. (3) Calculating waveforms from binary black hole mergers within a family of alternative gravitational theories in order to probe possible deviations from the predictions of general relativity and to search for new physics beyond our current model for gravity. 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.