Formula omitted]-mode oscillations of compact stars with realistic equations of state in dynamical spacetime

Abstract

In this study, we perform full three dimensional numerical relativity simulations of non-rotating general relativistic stars. Extending the studies for polytropic equation of state, we investigate the accuracy and robustness of numerical scheme on measuring fundamental (f)-mode frequency for realistic equations of state (EoS). We use various EoS with varying range of stiffness and numerically evolve perturbed stellar models for several mass configurations (in the range of 1.2−2.0M⊙) for each of these EoS. Using the gravitational waveform obtained from the simulations we extract the f-modes of the stars. The obtained results are tested against the pre-existing perturbation methods and find good agreement. Validity and deviation of universal relations have been carried out and are compared with earlier results under Cowling approximation as well as perturbative approaches. We also show that even using perturbed single star simulations can provide good agreement with f-modes extracted from inspiral phase of binary neutron star simulations which are computationally more expensive.