Modeling Neutron Star Matter in the Age of Multimessenger Astrophysics

Abstract

The interpretation of the available and forthcoming data obtained from multimessenger astrophysical observations-potentially providing unprecedented access to neutron star properties-will require the development of novel, accurate theoretical models of dense matter. Of great importance, in this context, will be the capability to devise a description of thermal effects applicable to the study of quantities other than the equation of state, such as the transport coefficients and the neutrino mean free path in the nuclear medium. The formalism based on correlated basis states and the cluster expansion technique has been previously employed to derive a well-behaved effective interaction-suitable for use in standard perturbation theory-from a state-of-the-art nuclear Hamiltonian, including phenomenological twoand three-nucleon potentials. Here, we provide a comprehensive and self-contained account of the extension of this approach to the treatment of finite-temperature effects, and report the results of numerical calculations of a number of properties of nuclear matter with arbitrary neutron excess and temperature up to 50 MeV.

Hidden-nucleons neural-network quantum states for the nuclear many-body problem

“…Exhaustive tests of nuclear interactions require many-body methods that are suitable to retain the complexity of nuclear dynamics at short distances [9,10]. An accurate description of the latter is also critical to reproduce exclusive lepton-nucleus scattering cross sections [11][12][13], for the calculation neutrinoless double-beta decay matrix elements [14], and for studying neutron-star matter in the high-density regime [8,9,15].…”