# Phenomenology of SUGRA Extensions of the Starobisnky Model

## TL;DR

This paper compares the Born-Infeld (BI) and Starobinsky inflation models, showing they produce similar inflation dynamics under Planck 2018 constraints, and explores parameter scales and inflation signatures.

## Contribution

It provides a complete analysis of the BI model, comparing its predictions with the Starobinsky model and examining parameter effects on inflation signatures.

## Key findings

- BI and Starobinsky models have nearly identical inflation dynamics under Planck constraints.
- Parameter scales and initial conditions for BI inflation are identified.
- Variations in parameters affect the spectral index and tensor-to-scalar ratio.

## Abstract

We analyze BI model in a complete form and compare the predictions with that of Starobinsky model. Under the parameter constraints in Planck 2018, we find that the dynamics of the whole inflation process described by BI and Starobinsky models are nearly the same, even though there are some differences in the regions out of inflation. We also find the scales of parameters in BI model and initial inflaton values required to implement inflation. The changes of $\left( {n}_{s}, r \right)$ fingerprints of BI model and that of evolutions of inflaton field due to the variations of relevant parameters are also investigated.