Viscous Bianchi Type I Universe with Stiff Matter and Decaying Vacuum Energy Density. (20th June 2012)

• Record Type: Journal Article
• Authors: Bali, Raj; Singh, Pratibha; Singh, J. P.
• Other Names: Lim S. C. Academic Editor.; Rasetti M. Academic Editor.
• Is Part Of: ISRN mathematical physics. Volume 2012(2012)
• Publication Date: 2012-06-20
• Subjects: Mathematical physics -- Periodicals; Mathematical physics; Electronic journals; Periodicals; 530.15
• DOI: 10.5402/2012/704612
• Languages: English
• ISSNs: 2090-4673

Abstract

Abstract : We examine homogeneous and anisotropic Bianchi type I cosmological model with viscous stiff matter and time-varying cosmological term Λ which scales with Hubble parameter H . The resulting model approaches isotropy. The cosmological term Λ relaxes to a genuine cosmological constant, and the model in the absence of bulk viscosity tends to a deSitter universe asymptotically. Our scenario presents an initial epoch with decelerating expansion followed by late-time acceleration consistent with observations. Bulk viscosity advances the accelerating phase in the model and prevents the matter density to vanish for large times.