New models of chaotic inflation in supergravity

TL;DR

This paper introduces a flexible class of supergravity-based chaotic inflation models with customizable potentials, including quadratic, symmetry-breaking, and power-law forms, and explores their inflationary predictions and stability features.

Contribution

It presents a new supergravity-inspired framework for chaotic inflation with adjustable potentials and nonminimal coupling, enhancing previous models with improved stability and broader phenomenological possibilities.

Findings

Potential forms include quadratic, symmetry-breaking, and power-law.

Spectral index n_s varies from 0.97 to 0.93 depending on parameters.

Tensor-to-scalar ratio r ranges from 0.3 to 0.01.

Abstract

We introduce a new class of models of chaotic inflation inspired by the superconformal approach to supergravity. This class of models allows a functional freedom of choice of the inflaton potential V = |f(\phi)|^2. The simplest model of this type has a quadratic potential m^2\phi^2/2. Another model describes an inflaton field with the standard symmetry breaking potential \lambda^2 (\phi^2-v^2)^2. Depending on the value of v and on initial conditions for inflation, the spectral index n_s may take any value from 0.97 to 0.93, and the tensor-to-scalar ratio r may span the interval form 0.3 to 0.01. A generalized version of this model has a potential \lambda^2 (\phi^\alpha-v^\alpha)^2. At large \phi and \alpha > 0, this model describes chaotic inflation with the power law potential \phi^{2\alpha}. For \alpha < 0, this potential describes chaotic inflation with a potential which becomes flat in the large field limit. We further generalize these models by introducing a nonminimal coupling of the inflaton field to gravity. The mechanism of moduli stabilization used in these models allows to improve and generalize several previously considered models of chaotic inflation in supergravity.