2005/11/30 by Xiang-Hua Zhai, Xiang-hua Zhai, Y. D. Xu +3 · 2 citations
Physics and Astronomy · #Attractor #Barotropic fluid #Black Holes and Theoretical Physics #Boundary value problem #Chaplygin gas #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Equation of state #Mathematical analysis #Mathematical physics #Mechanics #Physics #Quantum mechanics #Solar and Space Plasma Dynamics #Thermodynamics #Viscosity #Volume viscosity #astro-ph
paper · pdf · doi:10.1142/s0218271806008784
published as Int.J.Mod.Phys.D15:1151-1162,2006 · 8 pages, 5 eps figures, typos corrected
arxiv created 2006/01/24 · openalex publication_date 2006/08/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Viscous generalized Chaplygin gas (GCG) cosmology is discussed, assuming that there is bulk viscosity in the linear barotropic fluid and GCG. w γ = γ - 1 and w g represent the state equation parameters for barotropic fluid and GCG, respectively, in which γ = 1 or [Formula: see text] corresponds to ordinary matter or radiation. The dynamical analysis indicates that the phase [Formula: see text] is a dynamical attractor and the equation of state of GCG approaches it from either w g > -1 or w g < -1 depending on the choice of its initial cosmic density parameter and the ratio of pressure to critical energy density, where τ g and τ γ are viscosity parameters. Therefore, the equation of state w g will cross the boundary w g = -1 if we choose initial value w g < -1. Furthermore, we show that bulk viscosity coefficients should satisfy inequalities from the point of view of dynamics.