The observational status of simple in ationary models: an update

Abstract

We provide an update on ve relatively well-motivated in ationary models in which the in aton is a StandardModel singlet scalar eld. These include i) the textbook quadratic and quartic potential models but with additionalcouplings of the in aton to fermions and bosons, which enable reheating and also modify the naive predictions forthe scalar spectral indexnsandr, ii) models with Higgs and Coleman{Weinberg potentials, and nally iii) a quarticpotential model with nonminimal coupling of the in aton to gravity. Fornsvalues close to 0.96, as determined by theWMAP9 and Planck experiments, most of the considered models predictr≳0:02. The running of the scalar spectralindex, quanti ed byjdns=d lnkj, is predicted in these models to be of order 104{103