Nflation: observable predictions from the random matrix mass spectrum

TL;DR

This paper investigates Nflation models with random matrix-generated mass spectra, analyzing their observable predictions and compatibility with cosmic microwave background data.

Contribution

It provides a numerical analysis of density perturbation spectral indices in Nflation with random mass spectra, exploring various initial conditions and parameter spaces.

Findings

Spectral index varies with mass spectrum parameters.

Model remains viable with current microwave anisotropy data.

Tensor-to-scalar ratio matches single-field inflation predictions.

Abstract

We carry out numerical investigations of the perturbations in Nflation models where the mass spectrum is generated by random matrix theory. The tensor-to-scalar ratio and non-gaussianity are already known to take the single-field values, and so the density perturbation spectral index is the main parameter of interest. We study several types of random field initial conditions, and compute the spectral index as a function of mass spectrum parameters. Comparison with microwave anisotropy data from the Wilkinson Microwave Anisotropy Probe shows that the model is currently viable in the majority of its parameter space.