Density of dark matter in Solar system and perihelion precession of planets

Direct relation is pointed out between the secular perihelion precession of a planet and the density of dark matter at its orbit. It is valid under the only assumption that the density is spherically-symmetric, with the center coinciding with the Sun. This relation, combined with the observational data on perihelion precession of planets, results in upper limits on local values of the dark matter density in the Solar system.