Challenges in Particle Physics and Cosmology

We present the proposal that the superpartner of the goldstino (sgoldstino),which is the source of the supersymmetry breaking, acts as the inflaton. The so-called eta problem can be avoided by imposing a linear superpotential. The inflaton is charged under a gauged \(U(1)_R\) —symmetry. This creates an interesting class of small field inflation models with an inflationary plateau around the maximum of the scalar potential near the origin, where R-symmetry is restored as the inflaton rolls down to a minimum describing the current phase of the universe. The minimum has a positive tuneable vacuum energy, whereas the inflation can be caused by either an F- or a D-term. The models are consistent with cosmological evidence and anticipate a relatively low tensor-to-scalar ratio of primordial perturbations in the simplest scenario. We explored the inflaton’s decay modes after coupling it to the (supersymmetric) Standard Model, with the resulting reheating temperature being roughly \(10^8\) GeV.