Pole Inflation in Supergravity

TL;DR

This paper demonstrates how to realize chaotic inflation within Supergravity frameworks using specific logarithmic Kahler potentials that induce poles in the kinetic term, leading to viable inflation models with tunable parameters and observable predictions.

Contribution

It introduces a method to implement pole inflation in Supergravity with structured Kahler potentials, avoiding fine-tuning and matching observational data.

Findings

Models predict tensor-to-scalar ratio r around 0.001.

Tuning can be eliminated with more complex Kahler potentials.

Predicted spectral index aligns with current observations.

Abstract

We show how we can implement within Supergravity chaotic inflation in the presence of a pole of order one or two in the kinetic mixing of the inflaton sector. This pole arises due to the selected logarithmic Kahler potentials K, which parameterize hyperbolic manifolds with scalar curvature related to the coefficient -N of the logarithmic term. The associated superpotential W exhibits the same R charge with the inflaton-accompanying superfield and includes all the allowed terms. The role of the inflaton can be played by a gauge singlet or non-singlet superfield. Models with one logarithmic term in K for the inflaton, require N=2 and some tuning, of the order of 10^-5, between the terms of W and predict a tensor-to-scalar ratio r at the level of 0.001. The tuning can be totally eluded for more structured K's, with N values increasing with r and spectral index close or even equal to its present central observational value.