Gravitational wave asteroseismology of neutron stars with unified EOS: on the role of high-order nuclear empirical parameters

TL;DR

This paper investigates how high-order nuclear empirical parameters influence neutron star oscillations and tidal deformations, highlighting their significance for gravitational wave detection and potential to constrain nuclear physics parameters.

Contribution

It provides a detailed analysis of the sensitivity of neutron star oscillation modes and tidal responses to high-order nuclear empirical parameters, emphasizing their role in gravitational wave phenomena.

Findings

$K_{sym}$ affects fundamental mode frequencies in low-mass neutron stars.

$Q_{sym}$ and $Q_{sat}$ influence modes in intermediate and heavy neutron stars.

$Q_{sat}$ significantly decreases the first pressure mode regardless of star mass.

Abstract

We analyze the sensitivity of non-radial fluid oscillation modes and tidal deformations in neutron stars to high-order nuclear empirical parameters (NEP). In particular, we study the impact of the curvature and skewness of the symmetry energy $K_{\rm sym}$, $Q_{\rm sym}$, and the skewness of the binding energy in symmetric nuclear matter $Q_{\rm sat}$. As we are interested in the possibility of gravitational wave detection by future interferometers, we consider that the tidal interaction is the driving force for the quadrupolar non-radial fluid oscillations. We have also studied the correlations between those quantities, which will be useful to understand the strong physics of gravitational wave phenomena. Our main results show that $K_{\rm sym}$ impacts the frequencies of the fundamental mode mainly for low-mass neutron stars. The NEP $Q_{\rm sym}$ and $Q_{\rm sat}$ affect the fundamental modes of intermediate and heavy neutron stars, respectively. In the case of the first pressure mode, $K_{\rm sym}$ shows a small effect, while $Q_{\rm sat}$ shows a considerable decrease in this oscillation mode independent of the neutron star mass. Similarly, for tidal deformability, the NEP $Q_{\rm sat}$ and $Q_{\rm sym}$ show a bigger impact than $K_{\rm sym}$. Given the impact of the NEP on gravitational wave phenomena and the currently large uncertainties of these parameters, the prospect of higher sensitivity in future gravitational wave detectors promise a possible new tool to constrain high-order NEP.