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

TL;DR

This paper uses chiral effective field theory to calculate neutron star masses and radii, providing predictions consistent with recent observational constraints, especially focusing on the radius of a 1.4 solar mass neutron star.

Contribution

It presents the first detailed neutron star radius predictions based on chiral nucleon-nucleon potentials up to fifth order, including three-nucleon forces, and explores the impact of high-density extrapolations.

Findings

Predicted radius of a 1.4 M_{Sun} neutron star aligns with recent constraints.

Full mass-radius relations are provided up to maximum masses.

Radius is nearly insensitive to high-density extrapolation.

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.