# Non-minimally coupled nonlinear spinor field in FRW cosmology

## TL;DR

This paper investigates how a non-minimally coupled nonlinear spinor field influences the evolution of the universe in FRW cosmology, highlighting its role in rapid expansion or dark energy domination depending on the nonlinearity type.

## Contribution

It introduces analysis of non-minimal coupling of nonlinear spinor fields in FRW cosmology, exploring their effects on universe evolution with different nonlinearities.

## Key findings

- Non-minimal coupling leads to rapid expansion with radiation-like nonlinearity.
- Dark energy-like nonlinearity results in universe evolution dominated by the spinor field.
- Differences between minimal and non-minimal cases are negligible for dark energy scenarios.

## Abstract

Within the scope of a FRW cosmological model we have studied the role of spinor field in the evolution of the Universe when it is non-minimally coupled to the gravitational one. We have considered a few types of nonlinearity. It was found that if the spinor field nonlinearity describes an ordinary matter such as radiation, the presence of non-minimality becomes essential and leads to the rapid expansion of the Universe, whereas if the spinor field nonlinearity describes a dark energy, the evolution of the Universe is dominated by it and the difference between the minimal and non-minimally coupled cases become almost indistinguishable.