Inflation from supersymmetry breaking

Abstract

We explore the possibility that inflation is driven by supersymmetry breaking with the superpartner of the goldstino (sgoldstino) playing the role of the inflaton. Moreover, we impose an R-symmetry that allows one to satisfy easily the slow-roll conditions, avoiding the so-called η-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. To avoid the Goldstone boson and be left with a single (real) scalar field (the inflaton), Rsymmetry is gauged with the corresponding gauge boson becoming massive. This framework generalises a model studied recently by the present authors, with the inflaton identified by the string dilaton and R-symmetry together with supersymmetry restored at weak coupling, at infinity of the dilaton potential. The presence of the D-term allows a tuning of the vacuum energy at the minimum. The proposed models agree with cosmological observations and predict a tensorto-scalar ratio of primordial perturbations 10 −9 < ∼ r < ∼ 10 −4

Aspects of gauged R symmetry in SU(1,1)/U(Aldabergenov1 2020Phys. Rev. D4070View full textAdd to dashboardCite

“…6 The situation is somewhat similar to the construction of Refs. [18,19] where the Kähler potential is canonical (plus a quartic term), while the superpotential is linear due to the requirement of local R-symmetry. In this model viable hilltop inflation becomes possible only after including certain higher-order corrections to the Kähler potential.…”

Challenges in Supersymmetric Cosmology

“…For more details see [4,23] The scalar potential in the microscopic model considered in (16) is given by…”

“…However, such models require often trans-Planckian initial conditions that invalidate the effective supergravity description during inflation. A concrete example where all these problems appear is the Starobinsky model of inflation [3], despite its phenomenological success" [4].…”

“…In [4], we proposed a class of models that avoids all three problems above in which the inflaton is identified with the superpartner of goldstino (See [5][6][7][8] for earlier works relating supersymmetry and inflation), in the presence of a gauged R-symmetry. Indeed, the superpotential in this case is linear and cancels exactly the big contribution to η described above.…”

“…In a recent work [13], we studied the properties of the new FI term and explored its consequences to the class of inflation models we introduced in [4]. (The new FI term was also studied in [14] to remove an instability from inflation in Polonyi-Starobinsky supergravity.)…”