http://arxiv.org/abs/1807.10729
In the present paper, the effects of viscous dark matter are analysed. Here we consider bulk viscosity through the Israel-Stewart theory approach, leading to an effective pressure term in the continuity equation that accomplishes for the dissipative effects of the dark matter fluid. Then, the corresponding equation for viscosity is solved and a general equation for the Hubble parameter is obtained with the presence of a cosmological constant. The existence of de Sitter solutions is discussed, where a wider range of solutions is found. Also the conditions for the near thermodynamical equilibrium of the fluid is analysed. Finally, the model is constrained with Supernovae Ia data which reveals the importance of causal thermodynamics in cosmology .
N. Cruz, E. Gonzalez, S. Lepe, et. al.
Mon, 30 Jul 18
39/49
Comments: 11 pages, 4 figures
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