Interacting scalar and spinor fields in Bianchi type I universe filled with magneto-fluid

TL;DR

This paper derives exact solutions for a Bianchi type I universe filled with interacting scalar, spinor, and magneto-fluid fields, showing how the universe's anisotropy evolves depending on the cosmological constant.

Contribution

It provides new exact solutions for coupled scalar, spinor, and gravitational fields in Bianchi type I universe with magneto-fluid and cosmological constant.

Findings

Anisotropic universe becomes isotropic for non-positive Lambda.

Oscillatory expansion occurs for positive Lambda.

Exact metric and field solutions are obtained.

Abstract

Self-consistent system of spinor, scalar and BI gravitational fields in presence of magneto-fluid and $\Lambda$-term is considered. Assuming that the expansion of the BI universe is proportional to the $\sigma_1^1$ component of the shear tensor, exact solutions for the metric functions, as well as for scalar and spinor fields are obtained. For a non-positive $\Lambda$ the initially anisotropic space-time becomes isotropic one in the process of expansion, whereas, for $\Lambda > 0$ an oscillatory mode of expansion of the BI model occurs.