Dark matter local density determination: recent observations and future prospects

This report summarises progress made in estimating the local density of dark matter (rho(DM,circle dot)), a quantity that is especially important for dark matter direct detection experiments. We outline and compare the most common methods to estimate rho(DM,circle dot) and the results from recent studies, including those that have benefited from the observations of the ESA/Gaia satellite. The result of most local analyses coincide within a range of rho(DM,circle dot) similar or equal to 0.4-0.6GeVcm(-3) = 0.011-0.016M(circle dot)/pc(3), while a slightly lower range of rho(DM,circle dot) similar or equal to 0.3-0.5GeVcm(-3) = 0.008-0.013M(circle dot)/pc(3) is preferred by most global studies. In light of recent discoveries, we discuss the importance of going beyond the approximations of what we define as the ideal Galaxy (a steady-state Galaxy with axisymmetric shape and a mirror symmetry across the mid-plane) in order to improve the precision of rho(DM,circle dot) measurements. In particular, we review the growing evidence for local disequilibrium and broken symmetries in the present configuration of the Milky Way, as well as uncertainties associated with the galactic distribution of baryons. Finally, we comment on new ideas that have been proposed to further constrain the value of rho(DM,circle dot), most of which would benefit from Gaia's final data release.

Automated summary

This report summarizes progress made in estimating the local density of dark matter, discussing the range of results from local and global studies, as well as the importance of considering beyond the ideal Galaxy approximation. It also reviews evidence for local disequilibrium and broken symmetries in the present configuration of the Milky Way, and comments on new ideas proposed to further constrain the value of dark matter density.