Direct Detection of Dynamical Dark Matter
  Dynamical dark matter (DDM) is an alternative framework for dark-matter
physics in which the dark-matter candidate is an ensemble of constituent fields
with differing masses, lifetimes, and cosmological abundances. In this
framework, it is the balancing of these quantities against each other across
the ensemble as a whole which ensures phenomenological viability. In this
paper, we examine the prospects for the direct detection of a DDM ensemble. In
particular, we study the constraints imposed by current limits from
direct-detection experiments on the parameter space of DDM models, and we
assess the prospects for detecting such an ensemble and distinguishing it from
traditional dark-matter candidates on the basis of data from the next
generation of direct-detection experiments. For concreteness, we focus
primarily on the case in which elastic scattering via spin-independent
interactions dominates the interaction rate between atomic nuclei and the
constituent particles of the ensemble. We also briefly discuss the effects of
modifying these assumptions.
