Population Explosions and Gravitational-Wave Science

The detection of gravitational waves has opened an entirely new window on the universe. This award will support the analysis of the rapidly growing catalog of gravitational-wave sources—from the current catalog of 90 confirmed events to an expected 300+ by 2027—to unlock fundamental insights into black holes, neutron stars, and the expansion of the universe. By studying the population characteristics of these cosmic collisions, this research will advance our knowledge of how the most extreme objects in nature form and evolve, while simultaneously providing new ways to measure cosmic distances and test Einstein's theory of general relativity. This award directly serves the national interest by maintaining U.S. leadership in gravitational-wave science, training the next generation of scientists in cutting-edge data analysis techniques, developing innovative computational tools that benefit the broader scientific community and beyond, fostering innovation in data analysis, and establishing extensive educational outreach programs that serve communities in Chicago and nationwide.

This award focuses on the power of hundreds of gravitational-wave detections to provide qualitatively and quantitatively new insights into the field of gravitational-wave science. One theme of the work is gravitational-wave population astrophysics, which focuses on building the tools and analysis pipelines to answer some of the most exciting astrophysical questions related to LIGO sources. The award delves into the existence of a putative gap between the masses of the biggest neutron stars and the smallest black holes, and further explores implications for the formation mechanisms of both classes of compact objects. The award also studies the largest component black holes in the gravitational-wave catalogs. These sources are among the most surprising gravitational-wave discoveries to date, and there is much to learn about their properties and their astrophysical implications. The award will examine the gravitational lensing of gravitational waves, an entirely new scientific avenue which is only enabled by populations of at least hundreds, if not thousands of gravitational-wave sources. Work will also focus on standard siren cosmology, a uniquely clean and powerful gravitational-wave probe. Research will explore four standard siren approaches: bright sirens, dark sirens, spectral sirens, and Love sirens, including further development of the methodologies and implementations as the data sets grow and improve. Precision measurement of cosmological distances remains a topic of intense scientific fascination, and gravitational-wave sources are poised to make important contributions to this field. This award is at the forefront of gravitational-wave science and cuts across broad swaths of physics and astronomy, including nuclear physics, general relativity, astrophysics, cosmology, statistics, and data analysis.

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.

Award Number: 2513312
Principal Investigator: Daniel Holz
Funds Obligated: $300,000
State: IL