Quantum Field Theory of Interacting Dark Matter/Dark Energy: Dark
  Monodromies
  We discuss how to formulate a quantum field theory of dark energy interacting
with dark matter. We show that the proposals based on the assumption that dark
matter is made up of heavy particles with masses which are very sensitive to
the value of dark energy are strongly constrained. Quintessence-generated long
range forces and radiative stability of the quintessence potential require that
such dark matter and dark energy are completely decoupled. However, if dark
energy and a fraction of dark matter are very light axions, they can have
significant mixings which are radiatively stable and perfectly consistent with
quantum field theory. Such models can naturally occur in multi-axion
realizations of monodromies. The mixings yield interesting signatures which are
observable and are within current cosmological limits but could be constrained
further by future observations.
