Couplings and spectra in modular inflation

Abstract

We analyze how the spectrum of perturbations produced in a multicomponent modular inflation model proposed by Kadota and Stewart depends on couplings between the two moduli. Although some simple direct couplings give essentially the same results as the original model, dn/dlnk proportional to n-1, simple indirect couplings produce a power law spectrum, n-1=constant, which can naturally be close to scale invariant.