Dimensional Transmutation in Gravity and Cosmology
  We review (and extend) the analysis of general theories of all interactions
(gravity included) where the mass scales are due to dimensional transmutation.
Quantum consistency requires the presence of terms in the action with four
derivatives of the metric. It is shown, nevertheless, how unitary is achieved
and the classical Ostrogradsky instabilities can be avoided. The
four-derivative terms also allow us to have a UV complete framework and a
naturally small ratio between the Higgs mass and the Planck scale. Moreover,
black holes of Einstein gravity with horizons smaller than a certain
(microscopic) scale are replaced by horizonless ultracompact objects that are
free from any singularity and have interesting phenomenological applications.
We also discuss the predictions that can be compared with observations of the
microwave background radiation anisotropies and find that this scenario is
viable and can be tested with future data. Finally, how strong phase
transitions can emerge in models of this type with approximate scale symmetry
and how to test them with GW detectors is reviewed and explained.
