RUI: Neutron-Star Matter in the LIGO A+ Era and Beyond

Csu Fullerton Auxiliary Services Corporation, Fullerton CA

Investigators

Abstract

Neutron stars are critical sites for learning about the unknown structure and makeup of matter in its most extreme high-density form. Gravitational wave emission traces the dynamics of dense matter in neutron-star interiors, and the discovery of the binary neutron star merger GW170817 by the LIGO and Virgo Scientific Collaborations inaugurated the era of dense matter studies with gravitational waves. The research funded by this grant will support precision neutron-star matter science using future observations with upgraded LIGO and Virgo detectors, providing insight into forms of matter that cannot be recreated on Earth. It will engage and support undergraduate and Masters students at California State University Fullerton, a Hispanic-Serving Institution, in cutting-edge research at the intersection of nuclear physics and gravitational-wave astronomy. The phase evolution of the gravitational waves from a neutron star merger carries an imprint of the stars' internal structure. Currently, the only measurable matter signature is due to the leading-order tidal deformability parameter. However, improvements to detector sensitivities are poised to deliver louder and more numerous neutron star observations in the near future, unlocking the information encoded in next-to-leading-order tidal deformabilities and dynamical tides. In preparation for these future measurements, state-of-the-art infrastructure will be developed to connect gravitational-wave observables to the fundamental properties of dense matter, including its equation of state. In particular, this comprehensive Bayesian framework for inferring the equation of state will account for as-yet-unmeasured matter signatures, for uncertainty in the neutron star population, and for prior information from nuclear theory and electromagnetic observations of pulsars. These tools will be deployed to analyze future gravitational wave observations, helping to maximize the amount of dense matter knowledge they impart. 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.