This award supports the research activities of the University of Wisconsin-Milwaukee LIGO Scientific Collaboration (UWMLSC) group. The central theme of the project is the extraction of astrophysical information from gravitational-wave observations. Building on broad expertise, the group will engage in specific activities spanning all aspects of gravitational-wave astronomy. The award will foster synergy by focusing expertise in gravitational physics, astrophysics, and grid-computing on gravitational-wave data analysis challenges that are on the critical path to the scientific success of LIGO.
Gravitational waves are a fundamental prediction of Einstein's theory of general relativity. Yet almost 100 years after the theory was put forward these waves have eluded direct detection. Having recently constructed exquisitely sensitive detectors, such as LIGO, scientists from the United States and around the world are poised to make the first detection. With these instruments now operational, the challenge is to dig deep into their data to find the imprint of gravitational waves from astrophysical sources, such as black holes, neutron stars, and signals from the beginning of the universe. The first detection will usher in a new era of scientific discovery: the era of gravitational-wave astronomy. This work will make a significant contribution to many critical-path components of the LIGO data analysis effort, which will enable the first detection of gravitational waves and the wealth of astrophysical information thereby garnered. This award also supports research into the nature of highly energetic astrophysical sources of gravitational radiation which will provide valuable insight into the nature of Einstein's theory of gravity. Graduate students receive valuable training in the emerging field of gravitational wave science.
Gravitational waves are a fundamental prediction of Einstein's theory of general relativity. Yet almost 100 years after the theory was put forward these waves have eluded direct detection. Having recently constructed exquisitely sensitive detectors, such as LIGO, scientists from the United States and around the world are poised to make the first detections. With these instruments now operational, the challenge is to dig deep into their data to find the imprint of gravitational waves from astrophysical sources such as black holes, neutron stars, and signals from the beginning of the universe. The first detection will usher in a new era of scientific discovery. Intellectual merit This project supported research and development on several areas of gravitational physics, astrophysics, and data analysis challenges that are critical path to the success of LIGO. The inspiral and merger of binary black holes and neutron stars provided one of the most interesting venues for gravitational-wave and multi-messenger astronomy during the next decade. This project produced a number of critical enhancements to the search techniques and algorithms for inspiraling binary systems; determined the effects of spin on searches and their interpretation; developed searches triggered by gamma-ray bursts; and prototyped low-latency sky localization and triggering for electromagnetic observations. Bursts of waves from unexpected sources hold much promise for gravitational-wave astronomy. There is a broad vista of highly energetic astrophysical processes that may lead to significant gravitational-wave production including supernova core collapse, black hole mergers, and instabilities of neutron stars. This project provided tools needed to detect and interpret burst signals; in particular, gravitational waves from the ringdown of black holes and cosmic string cusps, and on follow-up searches of radio transients. Stochastic backgrounds of gravitational waves are created by the superposition of gravitational waves from multiple sources on the sky. This project contributed to the interpretation of gravitational wave searches for a stochastic gravitational wave background by showing how observational bounds constrain various models of early universe physics, such as a background created by bursts from cosmic strings. Continuous gravitational waves produced by rotating neutron stars are another candidate for gravitational wave detection. This project developed techniques to turn gravitational-wave observations into interesting astrophysical statements about neutron star populations and the physics of neutron stars, and contributed to continuous-wave searches that maximize detection probability using Einstein@Home as part of the pipeline. Other critical path components to LIGO data analysis produced by this project include the time-domain calibration of the detector's output, which is central to all LIGO observational activities. Broader impact In addition, this project developed collaborative research tools and facilitated broad collaboration and involvement in gravitational-wave astronomy. The project had a broad impact in training a new generation of graduate students, postdoctoral fellows and junior faculty members in gravitational wave astronomy. The excitement and promise of this new field of astrophysics has been spread locally and internationally through public outreach activities. For example, the Einstein@Home project has brought gravitational-wave data analysis to the homes and personal computers of over 200,000 people around the globe.
