RUI: Investigating Phases of Cosmic Matter with Neutron Star Seismology

Studying the properties of neutron stars helps us to better understand microscopic nuclear forces that govern the structure of sub-atomic matter. Neutron stars can also contain new forms of matter, such as dark matter, which is thought to make up about 27% of the matter in the Universe, and matter that displays unique collective behavior like superfluidity. This project will help in the discovery of such new states of matter, whose distinct features can be revealed by close examination of multi-messenger astronomical signals from neutron stars. Specifically, the PI will use mathematical and computational methods to quantify how neutron star composition affects observables such as gravitational waves. In addition to discovering new states of matter and energy, which is one of the biggest unanswered questions in Science, the PI will mentor several graduate students from diverse backgrounds and conduct synergistic outreach activities in local high schools to promote STEM learning from an early age. Just as helioseismology has proven to be a powerful tool to constrain theoretical models of the Sun and uncover beyond standard model physics, the growing field of neutron star seismology can reveal novel forms of strongly or weakly interacting matter and their behavior under extreme conditions. The PI and his students will quantify the spectrum of certain non-radial modes of neutron stars, called g-modes, that are particularly sensitive to temperature and composition, with the aim of establishing the link between manifest dense strongly interacting matter and its signature in gravitational waves resulting from neutron star mergers or core-collapse supernovae. In addition, the PI and his students will study the impact on neutron star oscillations of Bose condensates and dark matter admixtures, with the aim of constraining the condensate fraction, dark matter particle mass and its interactions with the strong force sector. This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments. 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.