Late-time behaviour of the tilted Bianchi type VI$_{-1/9}$ models

TL;DR

This paper investigates the long-term behavior of tilted Bianchi type VI_{-1/9} cosmological models with perfect fluids, revealing the existence of a closed curve attractor in models with vorticity through dynamical systems and numerical analysis.

Contribution

It provides a detailed analysis of the asymptotic evolution of tilted Bianchi VI_{-1/9} models, highlighting the role of vorticity and identifying new attractor structures.

Findings

Existence of a closed curve attractor in models with vorticity

Different asymptotic behaviors depending on vorticity presence

Insights into the future evolution of these cosmological models

Abstract

We study tilted perfect fluid cosmological models with a constant equation of state parameter in spatially homogeneous models of Bianchi type VI$_{-1/9}$ using dynamical systems methods and numerical simulations. We study models with and without vorticity, with an emphasis on their future asymptotic evolution. We show that for models with vorticity there exists, in a small region of parameter space, a closed curve acting as the attractor.