Halo cold dark matter and microlensing.

Abstract

We discuss expectations for the abundance of baryons and cold dark matter (CDM) in our own galactic halo and show that in plausible CDM models the local CDM density is at least ${10}^{\mathrm{\ensuremath{-}}25}$ g ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$. Based upon a suite of two-component halo models we conclude that the microlensing of stars in the Large Magellanic Cloud by dark halo stars is not a sensitive probe of the local CDM density. Thus, even if the number of candidate microlensing events increases significantly, experiments designed to detect halo CDM are still warranted.