# A General Classification of Starobinsky-like Inflationary Avatars of SU(2,1)/SU(2) x U(1) No-Scale Supergravity

## TL;DR

This paper provides a unified framework for classifying Starobinsky-like inflation models within no-scale supergravity, revealing six equivalence classes based on underlying symmetries, and aligning their predictions with CMB observations.

## Contribution

It introduces a general classification scheme for Starobinsky avatars in no-scale supergravity using SU(2,1)/SU(2) x U(1) symmetry, identifying six equivalence classes.

## Key findings

- Models predict small tensor-to-scalar ratio r consistent with CMB data
- Unified treatment demonstrates equivalences between different supergravity models
- Six distinct classes of models are identified based on symmetry considerations

## Abstract

Measurements of the cosmic microwave background (CMB) favour models of inflation with a small tensor-to-scalar ratio r, as predicted by the Starobinsky R + R^2 model. It has been shown previously that various models based on no-scale supergravity with different forms of superpotential make predictions similar to those of the Starobinsky model. In this paper we present a unified and general treatment of Starobinsky avatars of no-scale supergravity, using the underlying non-compact SU(2,1)/SU(2) x U(1) symmetry to demonstrate equivalences between different models, exhibiting 6 specific equivalence classes.