2006/01/24 by Iver Brevik · 57 citations
Mathematics · Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #COSMIC cancer database #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Curvature #Dark energy #Einstein #Geometry #Mathematical physics #Mathematics #Mechanics #Physics #Quantum gravity #Quantum mechanics #Quintessence #Relativity and Gravitational Theory #Scalar (mathematics) #Scalar curvature #Singularity #Theoretical physics #Thermodynamics #Viscosity #Viscous liquid #Volume viscosity #f(R) gravity #gr-qc #hep-th
paper · pdf · doi:10.1142/s0218271806008528
published in International Journal of Modern Physics D 15(05), 767-775 (World Scientific) · 12 pages, latex, no figures
arxiv created 2006/01/24 · openalex publication_date 2006/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider a modified form of gravity in which the action contains a power α of the scalar curvature. It is shown how the presence of a bulk viscosity in a spatially flat universe may drive the cosmic fluid into the phantom region (w < -1) and thus into a Big Rip singularity, even if it lies in the quintessence region (w > -1) in the nonviscous case. The condition for this to occur is that the bulk viscosity contains the power (2α-1) of the scalar expansion. Two specific examples are discussed in detail. The present paper is a generalization of the recent investigation dealing with barrier crossing in Einstein's gravity: I. Brevik and O. Gorbunova, Gen. Relativ. Gravit.37, 2039 (2005).