2004/06/30 by Alan A. Coley, Alan A Coley, Sigbjørn Hervik +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #gr-qc
paper · pdf · doi:10.1088/0264-9381/21/17/009
published as Class.Quant.Grav. 21 (2004) 4193-4208 · 16 pages, 1 figure, to appear in CQG
arxiv created 2004/06/30 · openalex publication_date 2004/08/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We use a dynamical systems approach to study Bianchi type VI 0 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-dimensional state space; these are consequently local attractors and serve as late-time asymptotes for an open set of tilted type VI 0 models containing two tilted fluids. We find that if one of the fluids has an equation of state parameter , the stiffest fluid will be dynamically insignificant at late times. For the value there is a two-dimensional bifurcation set and, if both fluids are stiffer than , both fluids will have extreme tilt asymptotically. We investigate in detail the case in which one fluid is extremely tilted. We also consider the case with one stiff fluid close to the initial singularity and find that the chaotic behaviour which occurs in general Bianchi models with is suppressed.