Halo Density Profiles Consistent with Asymmetric M-B Velocity Distributions-Implications on Direct Dark Matter Searches

TL;DR

This paper derives self-consistent WIMP velocity distributions from density profiles using the Eddington approach, exploring their implications for direct dark matter detection, including effects of asymmetry and velocity distribution shape.

Contribution

It introduces a method to obtain axially symmetric WIMP velocity distributions from density profiles, incorporating angular momentum dependence, and studies their impact on detection rates.

Findings

Some density profiles yield Maxwell-Boltzmann-like distributions

Distributions are naturally bounded by escape velocity

Asymmetry influences detection rate modulation

Abstract

In the present paper we obtain the WIMP velocity distribution in our vicinity starting from spherically symmetric WIMP density profiles in a self consistent way by employing the Eddington approach. By adding a reasonable angular momentum dependent term in the expression of the energy, we obtain axially symmetric WIMP velocity distributions as well. We find that some density profiles lead to approximate Maxwell-Boltzmann distributions, which are automatically defined in a finite domain, i.e. the escape velocity need not be put by hand. The role of such distributions in obtaining the direct WIMP detection rates, including the modulation, is studied in some detail and, in particular, the role of the asymmetry is explored.