Cosmological model with non-minimally coupled fermionic field

TL;DR

This paper proposes a cosmological model with a non-minimally coupled fermionic dark energy field, demonstrating its ability to replicate key observational features of the Universe's expansion and highlighting the coupling's influence on cosmological parameters.

Contribution

It introduces a novel non-minimally coupled fermionic field model for dark energy and analyzes its impact on cosmological evolution through numerical solutions.

Findings

Model reproduces red-shift behaviors of cosmological parameters

Coupling constant significantly affects density and deceleration parameters at low red-shift

Numerical solutions align with expected Universe expansion observations

Abstract

A model for the Universe is proposed whose constituents are: (a) a dark energy field modeled by a fermionic field non-minimally coupled with the gravitational field, (b) a matter field which consists of pressureless baryonic and dark matter fields and (c) a field which represents the radiation and the neutrinos. The coupled system of Dirac's equations and Einstein field equations is solved numerically by considering a spatially flat homogeneous and isotropic Universe. It is shown that the proposed model can reproduce the expected red-shift behaviors of the deceleration parameter, of the density parameters of each constituent and of the luminosity distance. Furthermore, for small values of the red-shift the constant which couples the fermionic and gravitational fields has a remarkable influence on the density and deceleration parameters.