Exploring the limits of nucleonic metamodeling using different relativistic density functionals

This is the authors' abstract. We don't add key points for this paper.

In this work, we explore two classes of density dependent relativistic mean-field models, their predictions of proton fractions at high densities and neutron star structure. We have used a metamodeling approach to these relativistic density functionals. We have generated a large ensemble of models with these classes and then applied constraints from theoretical and experimental nuclear physics and astrophysical observations. We find that both models produce similar equations of state and neutron star mass-radius sequences. But, their underlying compositions, denoted by the proton fraction in this case, are vastly different. This reinstates previous findings that information on composition gets masqueraded in β-equilibrium. Additional observations of nonequilibrium phenomena are necessary to pin it down.