Ab initio and phenomenological studies of the static response of neutron matter

TL;DR

This study uses advanced Monte Carlo simulations to analyze the static response of neutron matter under periodic modulation, providing insights relevant to neutron star crusts and neutron-rich nuclei.

Contribution

It combines ab initio Monte Carlo methods with phenomenological interactions to compute the static response and constrain energy-density functional theories.

Findings

Microscopic static response functions at various densities.

Constraints on isovector terms in energy-density functionals.

Insights into inhomogeneous neutron matter and astrophysical applications.

Abstract

We investigate the problem of periodically modulated strongly interacting neutron matter. We carry out ab initio non-perturbative auxiliary-field diffusion Monte Carlo calculations using an external sinusoidal potential in addition to phenomenological two- and three-nucleon interactions. Several choices for the wave function ansatz are explored and special care is taken to extrapolate finite-sized results to the thermodynamic limit. We perform calculations at various densities as well as at different strengths and periodicities of the one-body potential. Our microscopic results are then used to constrain the isovector term from energy-density functional theories of nuclei at many different densities, while making sure to separate isovector contributions from bulk properties. Lastly, we use our results to extract the static density-density linear response function of neutron matter at different densities. Our findings provide insights into inhomogeneous neutron matter and are related to the physics of neutron star crusts and neutron-rich nuclei.