Chain inflation and the imprint of fundamental physics in the CMBR

TL;DR

This paper explores how chain inflation can leave distinctive imprints on the cosmic microwave background radiation, revealing potential signatures of fundamental physics through modifications in the perturbation spectrum.

Contribution

It identifies two key effects of chain inflation on the CMB spectrum: spectral index modifications and spectrum modulation from bubble nucleation, linked to fundamental physics.

Findings

Spectral index depends on radiation-vacuum interactions.

Spectrum shows modulation indicating new physics.

Potential to extract fundamental physics information from CMB data.

Abstract

In this work we investigate characteristic modifications of the spectrum of cosmological perturbations and the spectral index due to chain inflation. We find two types of effects. First, modifications of the spectral index depending on interactions between radiation and the vacuum, and on features of the effective vacuum potential of the underlying fundamental theory. Second, a modulation of the spectrum signalling new physics due to bubble nucleation. This effect is similar to those of transplanckian physics. Measurements of such signatures could provide a wealth of information on the fundamental physics at the basis of inflation.