Nonlinear Spinor Fields in Bianchi type-III spacetime

TL;DR

This paper investigates how nonlinear spinor fields influence the evolution of anisotropic Bianchi type-III universe models, revealing conditions for accelerated or oscillatory expansion modes and the effects of gravity on spinor fields.

Contribution

It introduces a study of nonlinear spinor fields in Bianchi type-III spacetime, highlighting their impact on cosmic evolution and the role of gravity, which differs from other Bianchi types.

Findings

Models exhibit both accelerated and oscillatory expansion modes.

Non-diagonal energy-momentum components restrict metric and spinor field functions.

Mass and nonlinear terms of the spinor field do not vanish due to these restrictions.

Abstract

Within the scope of Bianchi type-III spacetime we study the role of spinor field on the evolution of the Universe as well as the influence of gravity on the spinor field. In doing so we have considered a polynomial type of nonlinearity. In this case the spacetime remains locally rotationally symmetric and anisotropic all the time. It is found that depending on the sign of nonlinearity the models allows both accelerated and oscillatory modes of expansion. The non-diagonal components of energy-momentum tensor though impose some restrictions on metric functions and components of spinor field, unlike Bianchi type I, V and $VI_0$ cases, they do not lead to vanishing mass and nonlinear terms of the spinor field.