Starobinsky-like Inflationary Models as Avatars of No-Scale Supergravity

TL;DR

This paper explores how Starobinsky-like inflationary models naturally arise from no-scale supergravity frameworks, analyzing their properties, stabilization mechanisms, and observational predictions relevant for current and future CMB experiments.

Contribution

It demonstrates the emergence of Starobinsky-like inflation models from no-scale supergravity and discusses their stabilization, generalizations, and observational implications.

Findings

Starobinsky-like models naturally emerge from no-scale supergravity.

Modulus stabilization techniques are discussed for inflation scenarios.

Models predict specific spectral tilt and tensor-to-scalar ratios testable by CMB experiments.

Abstract

Models of cosmological inflation resembling the Starobinsky R + R^2 model emerge naturally among the effective potentials derived from no-scale SU(N,1)/SU(N) x U(1) supergravity when N > 1. We display several examples in the SU(2,1)/SU(2) x U(1) case, in which the inflaton may be identified with either a modulus field or a matter field. We discuss how the modulus field may be stabilized in models in which a matter field plays the role of the inflaton. We also discuss models that generalize the Starobinsky model but display different relations between the tilt in the spectrum of scalar density perturbations, n_s, the tensor-to-scalar ratio, r, and the number of e-folds, N_*. Finally, we discuss how such models can be probed by present and future CMB experiments.