Isotropization in Bianchi type-I cosmological model with fermions and bosons interacting via Yukawa potential

TL;DR

This paper models the early Universe using a Bianchi type-I metric with fermionic and bosonic fields interacting via Yukawa potential, showing how these fields influence cosmic acceleration and isotropization over time.

Contribution

It introduces a cosmological model with fermions and bosons interacting through Yukawa potential, demonstrating their roles in early Universe acceleration and late-time isotropization.

Findings

Fermionic field exhibits negative pressure, bosonic field has small positive pressure.

Yukawa coupling affects the duration of the accelerated expansion.

Fermionic field drives late-time isotropization.

Abstract

In this work we investigate a model for the early Universe in a Bianchi type-I metric, where the sources of the gravitational field are a fermionic and a bosonic field, interacting through a Yukawa potential, following the standard model of elementary particles. It is shown that the fermionic field has a negative pressure, while the boson has a small positive pressure. The fermionic field is the responsible for an accelerated regime at early times, but since the total pressure tends to zero for large times, a transition to a decelerated regime occurs. Here the Yukawa potential answers for the duration of the accelerated regime, since by decreasing the value of its coupling constant the transition accelerated-decelerated occurs in later times. The isotropization which occurs for late times is due to the presence of the fermionic field as one of the sources of the gravitational field.