Linear response of homogeneous nuclear matter with energy density functionals

TL;DR

This paper develops a comprehensive framework to calculate the response functions of infinite nuclear matter with various isospin asymmetries using Skyrme energy density functionals, including new interaction components.

Contribution

It derives algebraic expressions for response functions from a general Skyrme functional, extending analysis to include new density-dependent and three-body terms.

Findings

Response functions for symmetric, neutron, and asymmetric nuclear matter are computed.

Analysis of spin-isospin strength functions under different conditions reveals potential instabilities.

The framework identifies conditions leading to physical and unphysical instabilities in nuclear matter.

Abstract

Response functions of infinite nuclear matter with arbitrary isospin asymmetry are studied in the framework of the random phase approximation. The residual interaction is derived from a general nuclear Skyrme energy density functional. Besides the usual central, spin-orbit and tensor terms it could also include other components as new density-dependent terms or three-body terms. Algebraic expressions for the response functions are obtained from the Bethe-Salpeter equation for the particle-hole propagator. Applications to symmetric nuclear matter, pure neutron matter and asymmetric nuclear matter are presented and discussed. Spin-isospin strength functions are analyzed for varying conditions of density, momentum transfer, isospin asymmetry, and temperature for some representative Skyrme functionals. Particular attention is paid to the discussion of instabilities, either real or unphysical, which could manifest in finite nuclei.