The equation of state of neutron matter, symmetry energy, and neutron star structure

TL;DR

This paper reviews quantum Monte Carlo calculations of neutron matter's equation of state, emphasizing three-neutron forces and their implications for neutron star properties and symmetry energy constraints.

Contribution

It combines QMC methods with theoretical models and observations to better constrain the symmetry energy and neutron star structure.

Findings

Three-neutron forces significantly affect the neutron matter equation of state.

Constraints on symmetry energy and its density dependence are improved.

Neutron star radius estimates are refined based on the equation of state.

Abstract

We review the calculation of the equation of state of pure neutron matter using quantum Monte Carlo (QMC) methods. QMC algorithms permit the study of many-body nuclear systems using realistic two- and three-body forces in a nonperturbative framework. We present the results for the equation of state of neutron matter, and focus on the role of three-neutron forces at supranuclear density. We discuss the correlation between the symmetry energy, the neutron star radius and the symmetry energy. We also combine QMC and theoretical models of the three-nucleon interactions, and recent neutron star observations to constrain the value of the symmetry energy and its density dependence.