Many-field Inflation: Universality or Prior Dependence?
  We investigate the observational signatures of many-field inflation and
present analytic expressions for the spectral index as a function of the prior.
For a given prior we employ the central limit theorem and the horizon crossing
approximation to derive universal predictions. These include a specific
dependence on the prior choice for initial conditions that has not been seen in
previous studies. Our main focus is on quadratic inflation, for which the
initial conditions statistics decouple from those of the mass distribution,
while other monomials are also briefly discussed. We verify the validity of our
calculations by comparing to full numerical simulations with 100 fields using
the transport method.
