Dark Matter Thermalization in Neutron Stars

TL;DR

This paper investigates how many-body effects like Pauli blocking and superfluidity influence dark matter thermalization times in neutron stars, impacting constraints on dark matter properties and suggesting possible exotic neutron star cores.

Contribution

It provides a detailed analysis of how many-body effects alter dark matter thermalization times in neutron stars, a novel consideration in dark matter-neutron star interactions.

Findings

Many-body effects lengthen DM thermalization time.

Constraints on DM mass and cross section are affected.

Exotic neutron star cores may be indicated by bosonic DM detection.

Abstract

We study how many-body effects alter the dark matter (DM) thermalization time inside neutron stars. We find that Pauli blocking, kinematic constraints, and superfluidity and superconductivity in the neutron star significantly affect the DM thermalization time, in general lengthening it. This could change the final DM mass and DM-nucleon cross section constraints by considering black hole formation in neutron stars due to DM accretion. We consider the class of models in which DM is an asymmetric, complex scalar particle with a mass between 1 keV and 5 GeV which couples to regular matter via some heavy vector boson. Interestingly, we find that the discovery of asymmetric, bosonic DM could motivate the existence of exotic neutron star cores. We apply our results to the case of mixed sneutrino DM.