Observational signatures of holographic models of inflation
  We discuss the phenomenology of recently proposed holographic models of
inflation, in which the very early universe is non-geometric and is described
by a dual three-dimensional quantum field theory (QFT). We analyze models
determined by a specific class of dual QFTs and show that they have the
following universal properties: (i) they have a nearly scale invariant spectrum
of small amplitude primordial fluctuations, (ii) the scalar spectral index runs
as alpha_s = -(n_s-1), (iii) the three-point function of primordial scalar
perturbations is of exactly the factorizable equilateral form with
f_nl^eq=5/36. These properties hold irrespective of the details (e.g. field
content, strength of interactions, etc.) of the dual QFT within the class of
theories we analyze. The ratio of tensors-to-scalars is determined by the field
content of the dual QFT and does not satisfy the slow-roll consistency
relations. Observations from the Planck satellite should be able to confirm or
exclude these models.
