The radius of a typical-mass neutron star and chiral effective field theory

Abstract

We calculate neutron star masses and radii from equations of state based on recent high-quality chiral nucleon-nucleon potentials up to fifth order of the chiral expansion and the leading chiral three- nucleon force. Our focus is on the radius of a 1.4 M_{Sun} neutron star, for which we report predictions that are consistent with the most recent constraints. We also show the full M(R) relations up to their respective maximum masses. Beyond the densities for which microscopic predictions are derived from chiral forces, the equations of state are obtained via polytropic continuations. However, the radius of a 1.4 M_{Sun} neutron star is nearly insensitive to the high-density extrapolation.