Constraining three-nucleon forces with multimessenger data

We report the results of a study aimed at inferring direct information on the repulsive three-nucleon potential VRijk—driving the stiffness of the nuclear matter equation of state at supranuclear densities—from astrophysical observations. Using a Bayesian approach, we exploit the measurements of masses, radii, and tidal deformabalities performed by the NICER satellite and the LIGO/Virgo Collaborations as well as the mass of the heaviest observed pulsar to constrain the strength of VRijk. The baseline of our analysis is the widely employed nuclear Hamiltonian comprising the Argonne v18 nucleon-nucleon potential and the Urbana IX model of the three-nucleon potential. The numerical results, largely determined by the bound on the maximum mass, suggest that existing and future facilities have the potential to provide valuable new insight into microscopic nuclear dynamics at supranuclear densities.