Bound on the dark matter density in the Solar System from planetary motions

High precision planet orbital data extracted from direct observation, spacecraft explorations, and laser ranging techniques enable to constrain the maximal dark matter density of a spherical halo centered around the Sun. If we assume a halo profile with a power-law dependence in the heliocentric distance, the maximal density at Earth’s location is of the order ${10}^5\mathrm{GeV}/{\mathrm{cm}}^3$. Moreover, this value shows only a mild dependence on the slope of the halo profile, taken between 0 and $-2$. This bound competes with that obtained from the perihelion precession limits.

Figure 1

Maximal allowed DM density at Earth’s location, as a function of the halo profile parameter $\gamma$.