Preheating after N-flation

We study preheating in N-flation, assuming the Marcenko-Pastur mass distribution, equal-energy initial conditions at the beginning of inflation and equal axion-matter couplings, where matter is taken to be a single, massless bosonic field. By numerical analysis we find that preheating via parametric resonance is suppressed, indicating that the old theory of perturbative preheating is applicable. While the tensor-to-scalar ratio, the non-Gaussianity parameters and the scalar spectral index computed for N-flation are similar to those in single-field inflation (at least within an observationally viable parameter region), our results suggest that the physics of preheating can differ significantly from the single-field case.