We use a dynamical systems approach to study Bianchi type VI0 cosmological models containing two tilted γ-law perfect fluids. The full state space is 11-dimensional, but the existence of a monotonic function simplifies the analysis considerably. We restrict attention to a particular, physically interesting, invariant subspace and find all equilibrium points that are future stable in the full 11...

In this paper we study the evolution of a LRS Bianchi I Universe, filled with a bulk viscous cosmological fluid in the presence of time varying constants " but " taking into account the effects of a c-variable into the curvature tensor. We find that the only physical models are those which " constants " G and c are growing functions on time t, while the cosmological constant Λ is a negative dec...

Homogeneous cosmological models with non-vanishing intrinsic curvature require a special treatment when they are quantized with loop quantum cosmological methods. Guidance from the full theory which is lost in this context can be replaced by two criteria for an acceptable quantization, admissibility of a continuum approximation and local stability. A quantization of the corresponding Hamiltonia...

We consider the dynamics towards the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The ‘Bianchi type IX attractor theorem’ states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of...

We study the evolution of the Weyl curvature invariant in all spatially homogeneous universe models containing a non-tilted γ-law perfect fluid. We investigate all the Bianchi and Thurston type universe models and calculate the asymptotic evolution of Weyl curvature invariant for generic solutions to the Einstein field equations. The influence of compact topology on Bianchi types with hyperboli...

Abstract We construct cosmological models for dark energy based on Lyra’s geometry the Bianchi-I space-time to understand evolution of universe. The specific choice deceleration parameter $$q=-\frac{\alpha _1}{t^2}+\alpha _2-1$$ q = - α ...

In this paper we study the dynamics of orthogonal spatially homogeneous Bianchi cosmologies in R-gravity. We construct a compact state space by dividing the state space into different sectors. We perform a detailed analysis of the cosmological behaviour in terms of the parameter n, determining all the equilibrium points, their stability and corresponding cosmological evolution. In particular, t...