CROSSING OF THE w= -1 BARRIER IN VISCOUS MODIFIED GRAVITY
نویسنده
چکیده
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 non-viscous 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. Grav. 37, 2039 (2005).
منابع مشابه
Crossing of the w= -1 barrier in two-fluid viscous modified gravity
Singularities in the dark energy late universe are discussed, under the assumption that the Lagrangian contains the Einstein term R plus a modified gravity term of the form Rα, where α is a constant. It is found, similarly as in the case of pure Einstein gravity [I. Brevik and O. Gorbunova, Gen. Rel. Grav. 37, 2039 (2005)], that the fluid can pass from the quintessence region (w > −1) into the ...
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