Radial oscillations in neutron stars from unified equation of states

Abstract

We study radial oscillations in non-rotating neutron stars by considering the unified equation of states (EoSs), which is consistent with finite nuclei and nuclear matter properties and supports the ≥ 2M star criterion. We solve the Sturm-Liouville problem to compute oscillation of f -mode frequency and their eigenfunction for neutron star modelled with six selected unified EoSs from two distinct Skyrme-Hartree Fock and Relativistic Mean-Field models. The calculated eigenfunction reveals the damped harmonic motion varying with the frequencies corresponding to EoS and with different central densities. We check the variation of f -mode frequency of oscillation with different quantities like central density, mass, average density and compactness of the neutron star. In particular, we derived an empirical relation for the frequency of f -mode scaled with central density as a function of the square of the average density and discovered a linear trend.

Radial Oscillations in Neutron Stars with Delta Baryons

“…Although the radial oscillation for the lowest order mode (n = 0) is not greatly impacted by the crust because it typically accounts for less than 10% of the stellar radius and the oscillation nodes are situated far inside the NS core. But other high oscillation modes are present in the crust of the star and hence the eigenfrequencies are modified (characterized by the peaks in the ∆ν n ) [34]. For a given EoS without crust, the variation in the frequency, ∆ν n , is smooth as discussed in Refs.…”

“…We investigate various radial oscillations of NSs with different matter compositions in this work. Several studies on the investigation of various radial oscillations of NSs with different exotic phases such as dark matter and deconfined quark matter have already been carried out [31,[33][34][35][36][37]. But the radial oscillation of NSs with ∆ baryons (∆-admixtured nucleonic stars) and hyperon stars with ∆ baryons (∆-admixtured hyperonic stars) is being studied for the first time.…”