Constraining Nuclear Parameters Using Gravitational Waves from f-mode Oscillations in Neutron Stars

Abstract

Gravitational waves (GWs) emanating from unstable quasi-normal modes in neutron stars (NSs) could be accessible with the improved sensitivity of the current GW detectors or with the next-generation GW detectors and, therefore, can be employed to study the NS interior. Assuming f-mode excitation in isolated pulsars with typical energy of pulsar glitches and considering potential f-mode GW candidates for A+ (upgraded LIGO detectors operating at fifth observing run design sensitivity) and Einstein Telescope (ET), we demonstrate the inverse problem of NS asteroseismology within a Bayesian formalism to constrain the nuclear parameters and NS equation of state (EOS). We describe the NS interior within relativistic mean-field formalism. Taking the example of glitching pulsars, we find that for a single event in A+ and ET, among the nuclear parameters, the nucleon effective mass (m*) within 90% credible interval can be restricted within 10% and 5%, respectively. At the same time, the incompressibility (K) and the slope of the symmetry energy (L) are only loosely constrained. Considering multiple (10) events in A+ and ET, all the nuclear parameters are well constrained, especially m*, which can be constrained to 3% and 2% in A+ and ET, respectively. Uncertainty in the observables of a 1.4 M ⊙ NS such as radius ( R 1.4 M ⊙ ), f-mode frequency ( f 1.4 M ⊙ ), damping time ( τ 1.4 M ⊙ ), and a few EOS properties including squared speed of sound (c s 2) are also estimated.

Cost of Inferred Nuclear Parameters toward the f-mode Dynamical Tide in Binary Neutron Stars

“…The simultaneous measurements of mass and tidal deformability of the NSs from GW measurements play a crucial role in improving the uncertainty in nuclear physics (Güven et al 2020;Traversi et al 2020;Biswas et al 2021;Lattimer 2021;Ghosh et al 2022aGhosh et al , 2022bImam et al 2022;Patra et al 2022;Beznogov & Raduta 2023;Mondal & Gulminelli 2023;Pradhan et al 2023aPradhan et al , 2023bHuang et al 2024). As the ignorance of the f-mode dynamical tides substantially affects the measurement of NS EOS and NS properties, this leads us to question how much bias one would expect on the nuclear parameters constrained using GW observations due to ignorance of f-mode dynamical tides.…”

Analysis of Neutron Star f-mode Oscillations in General Relativity with Spectral Representation of Nuclear Equations of State

“…Recent publications (Sotani 2021;Kunjipurayil et al 2022;Pradhan et al 2022Pradhan et al , 2023b show efforts to estimate nuclear matter parameters using stellar oscillation modes. Pradhan et al (2022) reported how the effective nucleon mass (m å ) at saturation is correlated with the f-mode frequencies for a set of EOSs generated within the RMF formalism.…”

Calibrating global behaviour of equation of state by combining nuclear and astrophysics inputs in a machine learning approach

“…Future, observations of coalescing BNS events by detectors like LIGO-Virgo-KAGRA, Einstein Telescope [17], and Cosmic Explorer [18] are likely to occur more frequently, enabling a more precise determination of the high-density part of the EoS [19][20][21][22][23][24][25][26][27][28][29][30][31]. The EoS at low densities ρ < 2ρ 0 are constrained by various nuclear physics experiments measuring the bulk properties of finite nuclei such as the nuclear masses, neutron skin thickness in 208 Pb, the dipole polarizability and isobaric analog states as well as the heavy-ion collisions.…”