English

Equilibrium points of the tilted perfect fluid Bianchi VI$_h$ state space

General Relativity and Quantum Cosmology 2009-11-10 v2

Abstract

We present the full set of evolution equations for the spatially homogeneous cosmologies of type VIh_h filled with a tilted perfect fluid and we provide the corresponding equilibrium points of the resulting dynamical state space. It is found that only when the group parameter satisfies h>1h>-1 a self-similar solution exists. In particular we show that for h>19h>-{\frac 19} there exists a self-similar equilibrium point provided that γ(2(3+h)5+3h,32)\gamma \in ({\frac{2(3+\sqrt{-h})}{5+3\sqrt{-h}}},{\frac 32}) whereas for h<19h<-{\frac 19} the state parameter belongs to the interval γ(1,2(3+h)5+3h)\gamma \in (1,{\frac{2(3+\sqrt{-h})}{5+3\sqrt{-h}}}) . This family of new exact self-similar solutions belongs to the subclass nαα=0n_\alpha ^\alpha =0 having non-zero vorticity. In both cases the equilibrium points have a five dimensional stable manifold and may act as future attractors at least for the models satisfying nαα=0n_\alpha ^\alpha =0. Also we give the exact form of the self-similar metrics in terms of the state and group parameters. As an illustrative example we provide the explicit form of the corresponding self-similar radiation model (γ=43\gamma={\frac 43}), parametrised by the group parameter hh. Finally we show that there are no tilted self-similar models of type III and irrotational models of type VIh_h.

Keywords

Cite

@article{arxiv.gr-qc/0407040,
  title  = {Equilibrium points of the tilted perfect fluid Bianchi VI$_h$ state space},
  author = {Pantelis S. Apostolopoulos},
  journal= {arXiv preprint arXiv:gr-qc/0407040},
  year   = {2009}
}

Comments

Latex, 17 pages, no figures; (v2) minor corrections, additional comments and 2 new references; revised version to appear in Gen. Rel. Grav