Using appropriate harmonics, we study the future asymptotic behavior of massless scalar fields on a class of cosmological vacuum spacetimes. The spatial manifold is assumed to be a circle bundle over a higher genus surface with a locally homogeneous metric. Such a manifold corresponds to the S̃L(2,R)-geometry (Bianchi VIII type) or the H × R-geometry (Bianchi III type). After a technical prepara...

Some spatially homogeneous Bianchi type I cosmological models filled with homogeneous “electric” p-form fields are shown to mimic the never-ending oscillatory behaviour of generic string cosmologies established recently. The validity of the “Kasner-free-flights plus collisions-on-potential-walls” picture is also illustrated in the case of known, non-chaotic, superstring solutions.

As a follow-up of recent article in which we investigated the cosmological background expansion history universe Bianchi type-V models with bulk viscous fluid and evolving Λ Newtonian G parameters, study evolution perturbations current work. In particular, analyse matter over-density that leads to formation large-scale structures Bianchi-V model, compare results standard ΛCDM solutions. Our sug...

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...

Centre manifold theory is applied to some dynamical systems arising from spatially homogeneous cosmological models. Detailed information is obtained concerning the late-time behaviour of solutions of the Einstein equations of Bianchi type III with collisionless matter. In addition some statements in the literature on solutions of the Einstein equations coupled to a massive scalar field are prov...