Gravimeter Search for Compact Dark Matter Objects Moving in the Earth

Dark matter could be composed of compact dark objects (CDOs). These objects may interact very weakly with normal matter and could move freely inside the Earth. A CDO moving in the inner core of the Earth will have an orbital period near 55 min and produce a time-dependent signal in a gravimeter. Data from superconducting gravimeters rule out such objects moving inside the Earth unless their mass m(D) and or orbital radius a are very small so that m(D)a < 1.2 x 10(-13)M(circle plus)R(circle plus). Here, M-circle plus and R-circle plus are the mass and radius of the Earth, respectively.