Effect of the equation of state for dilute neutron matter on the composition of the inner crust of neutron stars

Abstract

The composition of the inner crust of neutron stars is usually studied using phenomenological interactions such as Skyrme energy-density functionals. But most of these functionals do not agree well with ab-initio calculations of very dilute neutron matter. In this work, we study the inner crust of neutron stars in the model of phase coexistence of dense neutron-rich nuclear clusters and dilute neutron gas, and we investigate how employing a realistic microscopic equation of state to the neutron gas alters the composition. Our results indicate that with a functional that reproduces the correct equation of state of neutron matter at moderate densities, one can obtain a good description of the crust even if the functional does not have the correct behavior at extremely low density.