Volume 318 - Corfu Summer Institute 2017 "Schools and Workshops on Elementary Particle Physics and Gravity" (CORFU2017) - Workshop on the Standard Model and Beyond
Scale hierarchies and string phenomenology
We then generalise this model to a general class where the inflation is driven by supersymmetry breaking with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Imposing an R-symmetry allows to satisfy easily the slow-roll conditions, avoiding the so-called $\eta$-problem, and leads to two different classes of small field inflation models; they are characterised by an inflationary plateau around the maximum of the scalar potential, where R-symmetry is either restored or spontaneously broken, with the inflaton rolling down to a minimum describing the present phase of our Universe. The models agree with cosmological observations and predict a tensor-to-scalar ratio of primordial perturbations $10^{-9}<r<10^{-4}$ and an inflation scale $10^{10}$ GeV $<H_*<10^{12}$ GeV.}