An unified cosmological model driven by a scalar field nonminimally coupled to gravity

TL;DR

This paper presents a unified cosmological model where a nonminimally coupled scalar field explains inflation, dark matter, dark radiation, and dark energy, aligning well with observational data.

Contribution

It introduces a simple scalar field model with nonminimal coupling that naturally accounts for all major cosmic phases and components.

Findings

Inflation occurs naturally with slow-roll conditions.

The model reproduces observed density parameters.

Cosmic evolution phases appear naturally in the model.

Abstract

This paper consider an universe dominated by baryonic matter, radiation and a nonminimally coupled massive scalar field under the action of a symmetry breaking potential. Inflation occurs naturally with appropriated slow-roll values. The field evolves up to late times, when it is supposed to enter a slowing varying phase, remaining at rest at the value $\phi_0$. A mechanism for coupling the scalar field to baryonic and radiation energy densities through the nonminimal coupling $\xi$ is presented, leading naturally to dark matter and dark radiation components. A cosmological constant like term is also present, acting as a dark energy at late times. All the density parameters are in good agreement to observational data of Hubble measurements plus Supernovae Type Ia data. All the desired phases of cosmic evolution appears naturally in this simple model.