2009/11/28 by Xu Dou, Dou, Xu, Xin-He Meng +1
Physics and Astronomy · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #astro-ph.CO
paper · pdf · doi:10.48550/arxiv.0911.5401
11 pages, 7 figures
arxiv created 2010/01/31 · arxiv updated 2010/02/08
A general equation of state is used to model unified dark matter and dark energy (dark fluid), and it has been proved that this model is equivalent to a single fluid with time-dependent bulk viscosity. In this paper, we investigate scalar perturbation of this viscosity dark fluid model. For particular parameter selection, we find that perturbation quantity can be obtained exactly in the future universe. We numerically solve the perturbation evolution equations, and compare the results with those of ΛCDM model. Gravitational potential and the density perturbation of the model studied here have the similar behavior with the standard model, though there exists significant value differences in the late universe.