Dark Matter Effects on the Compact Star Properties

TL;DR

This study explores how fermionic dark matter interacting via Higgs exchange influences neutron star properties, revealing significant effects on maximum mass, tidal deformability, and gravitational wave signals during binary mergers.

Contribution

It introduces a model coupling dark matter with neutron star matter and analyzes its impact on star properties and gravitational wave signals, a novel approach in neutron star research.

Findings

Dark matter reduces the maximum neutron star mass.

Tidal and surficial Love numbers increase with more dark matter.

Dark matter significantly affects gravitational wave signals during late inspiral.

Abstract

The neutron star properties are generally determined by the equation of state of $\beta$-equilibrated dense matter. In this work, we consider the interaction of fermionic dark matter (DM) particles with the nucleons via Higgs exchange and investigate its effect on the neutron star properties with the relativistic mean-field model equation of state coupled with DM. We deduce that DM significantly affects the neutron star properties, such as considerably reduce the maximum mass of the star, which depends on the percentage of the DM considered inside the neutron star. The tidal Love numbers both for electric and magnetic cases and surficial Love numbers are also studied for DM admixed NS. It is observed that the magnitude of tidal and surficial Love numbers increase with more DM percentage. Further, we point out that post-Newtonian tidal corrections to gravitational waves decreased by increasing DM percentage. Also, the DM effect on the GW signal is significant during the late inspiral and merger stages of binary evolution for GW frequencies >500 Hz.