Expanding the Gravitational-Wave Detection Horizon to High Redshift

University Of California-Riverside, Riverside CA

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. In the last decade, gravitational wave astronomy has opened a new window into the Universe. A century after Einstein predicted gravitational waves, NSF's Laser Interferometer Gravitational-wave Observatory (LIGO) rewarded decades of investment with the first direct observations of gravitational waves from merging black holes and neutron stars. With improvements in sensitivity, gravitational-wave detectors will drive transformative discoveries across physics, astronomy, and cosmology in the coming decade, observing millions of black holes and neutron stars across cosmic time, probing the nature of the most extreme matter in the universe, and exploring open questions in gravity and fundamental physics. This award supports research to develop new adaptive optical technology critical to extending the astrophysical reach of gravitational-wave detectors and enabling future facilities. By clearing a key technological hurdle toward a next-generation gravitational-wave observatory, this award will ensure that gravitational-wave science continues inspiring young scientists across the country to fulfill their potential as the world-leading researchers of the future. The award will support the training of students in STEM areas. The main goal of this project is to develop and deploy new adaptive optical technology to improve the sensitivity of gravitational-wave detectors by a significant factor, expanding their detection horizon past a redshift of 5 and enabling new tests of strong-field gravity, cosmology, and dense nuclear matter. The project is integral to realizing a planned upgrade of the LIGO, known as A#, and will also help lay the foundation for a next-generation U.S.-based gravitational-wave observatory, Cosmic Explorer. These improvements primarily target LIGO's quantum-noise-limited detection band above 200 Hz, where some of the most impactful observations—black hole ringdowns and binary neutron star mergers (with potential particle or electromagnetic counterparts)—stand to be made. They will be achieved through improved control of thermal distortions of the optics, enabling a fourfold increase of the laser power, to 1.5 MW, and higher levels of squeezed light enhancement. Modeling indicates this will require a qualitatively new form of active wavefront correction in the test masses, targeting finer spatial scales. The proposed work will deliver these critical new corrective capabilities. 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.