Inflaton-driven early dark energy

TL;DR

This paper explores a model where inflaton-neutrino interactions produce a slowly varying early dark energy component that disappears before recombination, unifying inflation and dark energy with quantum fluctuations playing a key role.

Contribution

It demonstrates that quantum fluctuations in a mass-varying neutrino model can generate sufficient early dark energy, linking inflation and dark energy within a unified framework.

Findings

Quantum fluctuations can produce enough early dark energy.

The model remains stable under radiative and thermal corrections.

Early dark energy disappears before recombination.

Abstract

By arranging the control parameters, we examine whether the mass varying neutrino model PRD 103, 063540 (2021), enabling one to unify inflation with the present dark energy, can be used for producing an early dark energy. The model works in the following way. At early stages of the Big-Bang, the inflaton trapped in the minimum at $\phi = 0$ gets uplifted due to interaction with neutrinos and starts to roll down to one of the degenerate minima of the effective potential and after a while gets anchored at this minimum, which in turn evolves in time very slowly. Correspondingly, the early dark energy taking place as a result of this dynamical symmetry breaking also varies in time very slowly. Shortly before the recombination epoch, however, the symmetry is restored and early dark energy disappears. A typical problem of the mass varying neutrino models is that they can hardly provide the needed amount of early dark energy at the tree-level because of smallness of neutrino masses. Nevertheless, the quantum fluctuations of $\phi$ can do the job in providing sufficient early dark energy under assumption that inflationary energy scale is of the order of $1$\,TeV. Radiative as well as thermal corrections coming from the neutrino sector do not affect the model significantly. As for the gravity induced corrections to the effective potential - they can be safely ignored.