Axial Quasi-Normal Modes of Scalarized Neutron Stars with Realistic Equations of State

TL;DR

This paper analyzes the axial quasi-normal modes of scalarized neutron stars using realistic equations of state, revealing reduced frequencies and damping times compared to General Relativity, and confirming universal relations across different models.

Contribution

It extends the study of neutron star oscillations to scalar-tensor theories with realistic matter models, confirming universal mode relations in this context.

Findings

Reduced mode frequencies and damping times in scalarized stars

Universal relations hold for scalarized neutron stars

Mode properties depend on scalarization status

Abstract

We compute the axial quasi-normal modes of static neutron stars in scalar tensor theory. In particular, we employ various realistic equations of state including nuclear, hyperonic and hybrid matter. We investigate the fundamental curvature mode and compare the results with those of General Relativity. We find that the frequency of the modes and the damping time are reduced for the scalarized neutron stars. In addition, we confirm and extend the universal relations for quasi-normal modes known in General Relativity to this wide range of realistic equations of state for scalarized neutron stars and confirm the universality of the scaled frequency and damping time in terms of the scaled moment of inertia as well as compactness for neutron stars with and without scalarization.