Fermion field as inflaton, dark energy and dark matter

TL;DR

This paper explores how fermionic fields, through minimal and non-minimal gravitational couplings, can drive inflation, act as dark energy and dark matter, and produce accelerated expansion in the universe.

Contribution

It introduces a model where fermionic fields with specific potentials and couplings explain inflation, dark energy, and dark matter using Noether symmetry techniques.

Findings

Fermion fields can induce exponential inflation with non-minimal coupling.

Fermion fields can serve as dark energy and dark matter in cosmological models.

Non-minimal coupling leads to power-law inflation.

Abstract

The search for constituents that can explain the periods of accelerating expansion of the Universe is a fundamental topic in cosmology. In this context, we investigate how fermionic fields minimally and non-minimally coupled with the gravitational field may be responsible for accelerated regimes during the evolution of the Universe. The forms of the potential and coupling of the model are determined through the technique of the Noether symmetry for two cases. The first case comprises a Universe filled only with the fermion field. Cosmological solutions are straightforwardly obtained for this case and an exponential inflation mediated by the fermion field is possible with a non-minimal coupling. The second case takes account of the contributions of radiation and baryonic matter in the presence of the fermion field. In this case the fermion field plays the role of dark energy and dark matter, and when a non-minimal coupling is allowed, it mediates a power-law inflation.