Inflation from Nilpotent K\"ahler Corrections

TL;DR

This paper introduces a new supergravity inflation model driven by non-holomorphic K"ahler potential terms involving a nilpotent superfield, unifying inflation and dark energy with predictions matching Planck data.

Contribution

It presents a novel class of supergravity models where inflation is driven by K"ahler potential corrections involving nilpotent superfields, applicable to string theory scenarios.

Findings

Model naturally incorporates inflation and dark energy.

Small K"ahler corrections lead to $\

Predictions align with Planck data.

Abstract

We develop a new class of supergravity cosmological models where inflation is induced by terms in the K\"ahler potential which mix a nilpotent superfield $S$ with a chiral sector $\Phi$. As the new terms are non-(anti)holomorphic, and hence cannot be removed by a K\"ahler transformation, these models are intrinsically K\"ahler potential driven. Such terms could arise for example due to a backreaction of an anti-D3 brane on the string theory bulk geometry. We show that this mechanism is very general and allows for a unified description of inflation and dark energy, with controllable SUSY breaking at the vacuum. When the internal geometry of the bulk field is hyperbolic, we prove that small perturbative K\"ahler corrections naturally lead to $\alpha$-attractor behaviour, with inflationary predictions in excellent agreement with the latest Planck data