Oscillations of General Relativistic Multi-fluid/Multi-layer Compact Stars

TL;DR

This paper develops a formalism to analyze the quasinormal modes of multi-fluid, multi-layer relativistic compact stars, incorporating superfluid effects and realistic equations of state, advancing understanding of their oscillation dynamics.

Contribution

It introduces the first comprehensive approach to study true multi-layer superfluid compact stars with detailed modeling of entrainment and symmetry energy effects.

Findings

First to analyze true multi-layer dynamics in relativistic stars

Highlights the need for more complete equations of state including various physical parameters

Provides a framework to assess the impact of superfluid gap data on stellar oscillations

Abstract

We develop the formalism for determining the quasinormal modes of general relativistic multi-fluid compact stars in such a way that the impact of superfluid gap data can be assessed. Our results represent the first attempt to study true multi-layer dynamics, an important step towards considering realistic superfluid/superconducting compact stars. We combine a relativistic model for entrainment with model equations of state that explicity incorporate the symmetry energy. Our analysis emphasises the many different parameters that are required for this kind of modelling, and the fact that standard tabulated equations of state are grossly incomplete in this respect. To make progress, future equations of state need to provide the energy density as a function of the various nucleon number densities, the temperature (i.e. entropy), and the entrainment among the various components.