Modeling differential rotations of compact stars in equilibriums

TL;DR

This paper introduces new models for differential rotation in compact stars, providing solutions for equilibrium states and maximum mass limits, relevant for understanding neutron star formations after core collapse or mergers.

Contribution

It proposes novel formulations for modeling differential rotations in compact stars and presents solutions for equilibrium configurations and maximum mass calculations.

Findings

Derived solutions for differentially rotating, stationary, axisymmetric stars.

Identified maximum mass limits for stars reaching break-up velocities.

Enhanced understanding of rotational effects in neutron star stability.

Abstract

Outcomes of numerical relativity simulations of massive core collapses or binary neutron star mergers with moderate masses suggest formations of rapidly and differentially rotating neutron stars. Subsequent fall back accretion may also amplify the degree of differential rotations. We propose new formulations for modeling differential rotations of those compact stars, and present selected solutions of differentially rotating, stationary, and axisymmetric compact stars in equilibriums. For the cases when rotating stars reach break-up velocities, the maximum masses of such rotating models are obtained.