GSI Kolloquium: Dark Matter and the Nuclear Physics of its Detection

A variety of astronomical observations reveal that approximately 85% of the gravitating matter in our universe is dark, cold or warm, with weak interactions to ordinary matter and to itself. I will review efforts to detect dark matter (DM) by nuclear recoil, using specialized detectors mounted in deep underground locations to minimize backgrounds. I will argue that the nuclear physics of DM detection is more interesting than generally believed: in the context of effective theory, six response functions can be constructed, consistent with the good parity and time-reversal properties of nuclear ground states. Consequently nuclear physics provides six distinct "knobs" to turn, as experimentalists struggle to detect and determine the properties of DM.