  Gravitational backgrounds, such as black holes, AdS, de Sitter and
inflationary universes, should be viewed as composite of N soft constituent
gravitons. It then follows that such systems are close to quantum criticality
of graviton Bose-gas to Bose-liquid transition. Generic properties of the
ordinary metric description, including geodesic motion or particle-creation in
the background metric, emerge as the large-N limit of quantum scattering of
constituent longitudinal gravitons. We show that this picture correctly
accounts for physics of large and small black holes in AdS, as well as
reproduces well-known inflationary predictions for cosmological parameters.
However, it anticipates new effects not captured by the standard semi-classical
treatment. In particular, we predict observable corrections that are sensitive
to the inflationary history way beyond last 60 e-foldings. We derive an
absolute upper bound on the number of e-foldings, beyond which neither de
Sitter nor inflationary Universe can be approximated by a semi-classical
metric. However, they could in principle persist in a new type of it quantum
eternity state. We discuss implications of this phenomenon for the cosmological
constant problem.
