Abstract:
A novel idea of the direct detection to search for an ultralight dark matter
based on the interaction between the dark matter and a nucleon is proposed.
Solar system bodies feel the dark matter wind and it acts as a resistant force
opposing their motions. The astronomical ephemeris of solar system bodies
is so precise that it has a strong capability to detect a dark matter whose
mass is much lighter than O(1)eV. We have estimated the resistant force
based on the calculation of the elastic scattering cross section between the
dark matter and the bodies beyond the Born approximation, and show that
the astronomical ephemeris indeed put a very strong constraint on the
interaction between the dark matter and a nucleon.