Perturbative approach to the structure of rapidly rotating neutron stars

TL;DR

This paper develops a perturbative method to model rapidly rotating neutron stars, extending Hartle's approach to third order in angular velocity, and compares results with non-linear codes to assess accuracy.

Contribution

It introduces a third-order perturbative framework for neutron star modeling and evaluates its precision against fully non-linear simulations.

Findings

Third order corrections improve moment of inertia estimates for fast rotators.

Perturbative results closely match non-linear codes at high rotation rates.

The method offers a computationally efficient alternative for neutron star modeling.

Abstract

We construct models of rotating stars using the perturbative approach introduced by J. Hartle in 1967, and a set of equations of state proposed to model hadronic interactions in the inner core of neutron stars. We integrate the equations of stellar structure to third order in the angular velocity and show, comparing our results to those obtained with fully non linear codes, to what extent third order corrections are needed to accurately reproduce the moment of inertia of a star which rotates at rates comparable to that of the fastest isolated pulsars.