Rotating star initial data for a constrained scheme in numerical relativity

TL;DR

This paper introduces a new numerical code for modeling rapidly rotating stars in general relativity, demonstrating its accuracy and versatility with different equations of state and comparing it to existing methods.

Contribution

The paper presents a novel constrained-evolution numerical scheme using the Dirac gauge for rotating star models in general relativity.

Findings

The code accurately constructs rapidly rotating neutron and strange star models.

Results agree closely with established codes using different gauge conditions.

The scheme effectively handles various equations of state for compact stars.

Abstract

A new numerical code for computing stationary axisymmetric rapidly rotating stars in general relativity is presented. The formulation is based on a fully constrained-evolution scheme for 3+1 numerical relativity using the Dirac gauge and maximal slicing. We use both the polytropic and MIT bag model equations of state to demonstrate that the code can construct rapidly rotating neutron star and strange star models. We compare numerical models obtained by our code and a well-established code, which uses a different gauge condition, and show that the two codes agree to high accuracy.