Nuclear Physics from Multi-Messenger Mergers (NP3M)

Recent advances in nuclear theory, artificial intelligence (AI), large-scale astrophysical simulations, and multi-messenger astronomy have created unprecedented opportunities to connect observations of neutron stars with the fundamental properties of dense nuclear matter. The Nuclear Physics from Multi-Messenger Mergers (NP3M) Focus Research Hub leads a coordinated effort that integrates nuclear theory, AI, and state-of-the-art neutron star merger simulations to probe the behavior of hot, dense strongly interacting matter through multi-messenger observations. NP3M addresses key questions about the nature of matter in neutron star interiors, the connection between nuclear physics and observable merger signals, and the role of collider experiments in constraining the interactions that govern neutron stars and their mergers. AI is central to NP3M’s success, enabling efficient analysis of complex, computationally intensive simulations and unlocking scientific insights that are inaccessible through traditional approaches. The work directly supports national priorities in AI by leveraging advanced methodologies to accelerate discovery and enhance research productivity. NP3M is providing a new generation of postdoctoral scholars with the broad training in nuclear physics, AI, computational astrophysics, and multi-messenger astronomy needed to maximize the federal government’s investment in national facilities through programs like Advanced LIGO, the Facility for Rare Isotope Beams, and the Vera Rubin observatory. The NP3M Hub is an interdisciplinary collaboration spanning nuclear physics, artificial intelligence, astrophysics, and gravitational-wave science, aimed at advancing the coordinated developments required to interpret multi-messenger observations. The volume, precision, and complexity of data anticipated from next-generation facilities demand an AI-assisted, coordinated theoretical response to ensure that their scientific potential is fully realized. NP3M builds theoretical models of dense, hot matter that link neutron star observations to merger dynamics through large-scale numerical simulations. The hub represents an integrated effort to quantify how uncertainties in nuclear physics and computational modeling affect end-to-end predictions of multi-messenger signals from neutron star mergers. NP3M relies on strong collaborations between nuclear theorists and astrophysicists to develop state-of-the-art nuclear input and implement it in simulations of neutron star mergers, including their electromagnetic, neutrino, and gravitational-wave emissions. A central goal of the hub is to advance our understanding of the equation of state and the behavior of strongly interacting matter under the extreme conditions found in neutron star interiors and mergers. This work paves the way toward constraining the dense-matter region of the Quantum Chromodynamics (QCD) phase diagram, which remains largely unexplored. NP3M will engage the broader scientific community to advance progress in nuclear theory and astrophysics. 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.