Corpuscular slow-roll inflation

TL;DR

This paper proposes a corpuscular model of gravity that naturally produces an inflationary universe similar to Starobinsky's without an inflaton, based on the properties of a graviton condensate.

Contribution

It introduces a novel corpuscular framework for inflation, linking the inflationary dynamics to the quantum properties of gravitons in a condensate.

Findings

Reproduces inflationary relations without inflaton fields

Derives the Hubble parameter and slow-roll conditions from graviton properties

Aligns with CMB observational constraints

Abstract

We show that a corpuscular description of gravity can lead to an inflationary scenario similar to Starobinsky's model without requiring the introduction of the inflaton field. All relevant properties are determined by the number of gravitons in the cosmological condensate or, equivalently, by their Compton length. In particular, the relation between the Hubble parameter $H$ and its time derivative $\dot H$ required by CMB observations at the end of inflation, as well as the (minimum) initial value of the slow-roll parameter, are naturally obtained from the Compton size of the condensate.