Anisotropic cosmological models with spinor field and viscous fluid in presence of a $\Lambda$ term: qualitative solutions

TL;DR

This paper performs a qualitative analysis of anisotropic cosmological models involving nonlinear spinor fields, viscous fluids, and a cosmological constant, classifying possible universe evolution scenarios.

Contribution

It provides a comprehensive qualitative classification of universe evolution modes in models with nonlinear spinor fields, viscous fluids, and a $\\Lambda$ term, extending previous analyses.

Findings

Classified various evolution modes of the universe.

Identified conditions leading to different cosmological behaviors.

Analyzed the impact of spinor nonlinearity and viscosity on dynamics.

Abstract

The study of a self-consistent system of nonlinear spinor and Bianchi type I gravitational fields in presence of a viscous fluid and $\Lambda$ term with the spinor field nonlinearity being some arbitrary functions of the invariants $I$ an $J$ constructed from bilinear spinor forms $S$ and $P$, generates a multi-parametric system of ordinary differential equations \cite{saharrp,grqcnlsp}. A qualitative analysis of the system in question has been thoroughly carried out. A complete qualitative classification of the mode of evolution of the universe given by the corresponding dynamic system has been illustrated.