Cosmological scenarios from topological invariants: Inflation and Quintom theory with Barbero-Immirzi scalar field

TL;DR

This paper explores cosmological models derived from the Palatini action with topological invariants, leading to scalar fields influencing inflation and quintom scenarios, emphasizing the role of torsion and the Barbero-Immirzi field.

Contribution

It introduces a novel cosmological framework incorporating topological invariants and torsion, resulting in dynamical scalar fields affecting early and late universe evolution.

Findings

Two scalars are identified as the Barbero-Immirzi field with potential-driven dynamics.

A phantom scalar couples to the inflaton, inducing rapid late-time expansion.

The model provides a unified description of inflation and quintom behavior.

Abstract

In the present work we provide a cosmological description of the Palatini action with the addition of three well-known topological invariants, each of which is attached to a scalar field. As a consequence, torsion plays a central role, yielding an effective action with three dynamical scalar fields coupled to gravity subjected to the influence of a potential. A special heed will be addressed to inflation scenarios and quintom theory, although other noteworthy cases will be analyzed. Two out of three scalars can be thought as the Barbero-Immirzi scalar field coupled to the Holst and Nieh-Yan terms with a potential whereby they shape the evolution of the universe. The other field turns out to be a phantom that we couple to the inflaton that at late times holds the stage inducing a fast expansion