Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars

TL;DR

This paper reviews recent experimental constraints on nuclear symmetry energy and explores its effects on neutron star properties, including binding energy, phase transitions, and gravitational wave signals.

Contribution

It synthesizes recent experimental data and theoretical studies to elucidate how nuclear symmetry energy influences neutron star characteristics.

Findings

Constraints on symmetry energy at sub-saturation densities are narrowing.

Symmetry energy impacts neutron star binding energy and phase transition energetics.

Effects on gravitational wave modes provide potential observational signatures.

Abstract

Significant progress has been made in recent years in constraining the density dependence of nuclear symmetry energy using terrestrial nuclear laboratory data. Around and below the nuclear matter saturation density, the experimental constraints start to merge in a relatively narrow region. At supra-saturation densities, there are, however, still large uncertainties. After summarizing the latest experimental constraints on the density dependence of nuclear symmetry energy, we highlight a few recent studies examining imprints of nuclear symmetry energy on the binding energy, energy release during hadron-quark phase transitions as well as the $w$-mode frequency and damping time of gravitational wave emission of neutron stars.