Dark Matter Effects On Neutron Star Properties

TL;DR

This paper investigates how dark matter cores within neutron stars can influence their maximum mass, size, and deformability, potentially affecting the interpretation of astrophysical data and constraints on nuclear matter models.

Contribution

It demonstrates that dark matter cores of about 5% mass fraction can significantly alter neutron star properties and impact the constraints on nuclear equations of state derived from observations.

Findings

Dark matter cores reduce neutron star maximum mass and radius.

Presence of dark matter cores affects tidal deformability measurements.

Certain dark matter scenarios can reconcile neutron star data with specific EOS models.

Abstract

We study possible effects of a dark matter (DM) core on the maximum mass of a neutron star (NS), on the mass-radius relation and on the NS tidal deformability parameter $\Lambda$. We show that all these quantities would in general be reduced in the presence of a DM core. In particular, our calculations indicate that the presence of a DM core with a mass fraction $\sim 5\%$ could affect significantly the interpretation of these NS data as constraints on the nuclear equation of state (EOS), potentially excluding some EOS models on the basis of the measured mass of PSR J0348+0432, while allowing other EOS models to become consistent with the LIGO/Virgo upper limit on $\Lambda$. Specific scenarios for generating such DM cores are explored in an Appendix.