Enhancement of dark matter capture by neutron stars in binary systems

TL;DR

This paper investigates how dark matter particles are more efficiently captured by neutron stars in close binary systems, showing a significant increase in capture rate due to gravitational interactions.

Contribution

It provides the first numerical simulation demonstrating the amplification of dark matter capture in binary neutron star systems, quantifying the effect for specific pulsars.

Findings

Capture rate amplification factor of 3.5 for PSR J1906+0746

Gravitational scattering causes energy loss in dark matter particles

Close binary systems enhance dark matter accumulation in neutron stars

Abstract

We study the capture of dark matter particles by neutron stars in close binary systems. By performing a direct numerical simulation, we find that there is a sizable amplification of the rate of dark matter capture by each of the companions. In case of the binary pulsar PSR J1906+0746 with the orbital period of 4 hours the amplification factor is 3.5. This amplification can be attributed to the energy loss by dark matter particles resulting from their gravitational scattering off moving companions.