Coupled inflaton and electromagnetic fields from Gravitoelectromagnetic Inflation with Lorentz and Feynman gauges

TL;DR

This paper investigates the origin and evolution of inflaton and electromagnetic fields during early inflation using a 5D vacuum model with Lorentz and Feynman gauges, revealing scale-dependent electric field spectra.

Contribution

It introduces a novel 5D semiclassical formalism for inflationary electromagnetic fields that is not conformally invariant, enabling super adiabatic amplification of fields during inflation.

Findings

Electric and magnetic fields are amplified during inflation.

Electric field spectral index increases quadratically with decreasing scale.

First systematic analysis of electric field fluctuations in 4D inflation models.

Abstract

Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of electric and magnetic field modes during the early inflationary epoch of the universe on cosmological scales. This is the first time that solutions for the electric field fluctuations are investigated in a systematic way as embeddings for inflationary models in 4D. An important and new result here obtained is that the spectrum of the electric field fluctuations depend with the scale, such that the spectral index increases quadratically as the scale decreases.