Fermionic and scalar fields as sources of interacting dark matter-dark energy

TL;DR

This paper develops a cosmological model with interacting dark matter and dark energy derived from a variational action involving non-minimal coupling, scalar, and fermionic fields, allowing for dynamic behavior including crossing from quintessence to phantom regimes.

Contribution

It introduces a novel interacting dark sector model based on non-minimal coupling with scalar and fermionic fields, providing analytical and numerical insights into its cosmological implications.

Findings

Model allows crossing from quintessence to phantom behavior.

Solutions are largely insensitive to certain parameters.

An almost analytical solution for a cosmological constant universe.

Abstract

From a variational action with non-minimal coupling with a scalar field and classical scalar and fermionic interaction, cosmological field equations can be obtained. Imposing a FLRW metric the equations lead directly to a cosmological model consisting of two interacting fluids, where the scalar field fluid is interpreted as dark energy and the fermionic field fluid is interpreted as dark matter. Several cases were studied analytically and numerically. An important feature of the non-minimal coupling is that it allows crossing the barrier from a quintessence to phantom behavior. The insensitivity of the solutions to one of the parameters of the model permits it to find an almost analytical solution for the cosmological constant type of universe.