Rapidly spinning dark matter-admixed neutron stars

TL;DR

This paper models rapidly rotating neutron stars with dark matter components that can rotate independently, exploring how dark matter affects their physical properties and offering insights into dark matter's astrophysical role.

Contribution

It introduces a novel model of rotating neutron stars with independent dark matter rotation, analyzing its effects on star properties across various dark matter scenarios.

Findings

Dark matter rotation significantly alters mass-radius relations.

Dark matter presence affects the mass-shedding limit.

Different dark matter distributions impact moments of inertia.

Abstract

Millisecond pulsars, representing the older neutron star population, are believed to have undergone a prolonged period of dark matter accumulation, resulting in a higher dark matter content. Their extreme rotation makes them unique laboratories for studying rapidly rotating neutron stars admixed with dark matter. In this work, we model uniformly rotating neutron stars with a dark matter component that rotates independently from the baryon matter, allowing for the investigation of both co-rotating and counter-rotating scenarios. We examine the impact of dark matter rotation on the macroscopic properties of neutron stars, including the mass-radius relation, the mass-shedding Keplerian limit, and moments of inertia, for various dark matter particle masses and total fractions, considering both core and halo distributions. Our findings provide a more comprehensive understanding of how dark matter influences the equilibrium properties of rotating neutron stars, offering new insights into the astrophysical implications of self-interacting dark matter.