Vainshtein in the UV and a Wilsonian analysis of derivatively coupled
  scalars
  In the first part of this paper we critically examine the ultra-violet
implications of theories that exhibit Vainshtein screening, taking into account
both the standard Wilsonian perspective as well as more exotic possibilities.
Aspects of this discussion draw on results from the second part of the paper in
which we perform a general study of derivatively coupled scalar theories using
non-perturbative exact renormalisation group techniques, which are of interest
independently of their application to modified gravity. In this context, we
demonstrate the suppression of quantum corrections within the Vainshtein radius
and discuss the potential relation with the classicalisation conjecture. We
question whether the latter can be considered a realistic candidate for UV
completion of large-scale modifications of gravity on account of a dangerously
low classicalisation/strong coupling scale.
