Non-gaussianity in axion N-flation models: detailed predictions and mass
  spectra
  We have recently shown that multi-field axion N-flation can lead to
observable non-gaussianity in much of its parameter range, with the assisted
inflation mechanism ensuring that the density perturbations are sufficiently
close to scale invariance. In this paper we extend our analysis in several
directions. In the case of equal-mass axions, we compute the probability
distributions of observables and their correlations across the parameter space.
We examine the case of unequal masses, and show that the mass spectrum must be
very densely packed if the model is to remain in agreement with observations.
The model makes specific testable predictions for all major perturbative
observables, namely the spectral index, tensor-to-scalar ratio, bispectrum, and
trispectrum.
