Singularities in the Gravitational Capture of Dark Matter through Long-Range Interactions

Understand

We re-examine the gravitational capture of dark matter (DM) through long-range interactions.

• We demonstrate that neglecting the thermal motion of target particles, which is often a good approximation for short-range capture, results in parametrically inaccurate results for long-range capture.
• When the particle mediating the scattering process has a mass that is small in comparison to the momentum transfer in scattering events, correctly incorporating the thermal motion of target particles results in a quadratic, rather than logarithmic, sensitivity to the mediator mass, which substantially enhances the capture rate.
• We quantitatively assess the impact of this finite temperature effect on the captured DM population in the Sun as a function of mediator mass.