Keeping the relation between the Starobinsky model and no-scale supergravity ACTive
Ioannis D. Gialamas, Theodoros Katsoulas, K. Tamvakis
Abstract
Abstract We introduce a modification of the Starobinsky model in the form of an additional cubic Ricci scalar curvature term ∼ αR 3 , scaled by a dimensionless parameter α , with the resulting inflaton potential being the standard Starobinsky potential modified to first parametric order by an additive term. The resulting potential is identical to the potential obtained by a modification of the superpotential employed in the construction of the Starobinsky model in the framework of no-scale supergravity, thus, extending the correspondence between a class of no-scale supergravity models and modifications of the Starobinsky model. We analyze the inflationary predictions of the model and find that for -4.2 × 10 -5 ≲ α ≲ -1.9 × 10 -5 , the modified Starobinsky model is in full agreement with the recent observational data from the Atacama Cosmology Telescope, for a range of e -folds, N ★ = 50–60.