Non-radial oscillations and global stellar properties of anisotropic compact stars using realistic equations of state

TL;DR

This paper investigates how anisotropic effects influence the gravitational wave frequencies and global properties of compact stars using realistic equations of state, extending previous polytropic models to more complex matter descriptions.

Contribution

It introduces a systematic analysis of anisotropic effects on compact stars with realistic equations of state, linking anisotropy to observable stellar properties and data.

Findings

Anisotropic effects significantly impact gravitational wave frequencies.

The anisotropic parameter can be tuned to match observational data.

Global stellar quantities are affected by anisotropy and equation of state.

Abstract

In this work, we have made a systematic study of how the gravitational wave frequency of the fundamental mode from compact stars is affected by anisotropic effects using realistic equations of state. Our study is an extension of the seminal research performed by Doneva [Phys. Rev. D 85 (2012) 124023], where a polytropic equation of state was used. To achieve our objective, we considered compact stars which were built by using equations of state in the framework of a relativistic mean field theory for the case of hadronic stars and in the framework of the MIT model for the case of quark stars. In order to obtain some pertinent information that could give us the possibility to detect the anisotropy in compact stars, we also studied and analized the behaviour of various global stellar quantities, e.g., gravitational redshift, stellar mass, radius, among others. We concluded that the anisotropic effects can have important consequences, which are strongly related to the anisotropic parameter and the equation of state of high density matter. Additionally, a comparison with observational data has been made and we have shown that the anisotropic parameter $\lambda$ can be used as a tuning parameter to reproduce mass and radius observational data of neutron stars.